Development of Co-Rich Microwires with Graded Magnetic Anisotropy

In this paper, a gradual change in the hysteresis loop of Co-rich glass-coated microwire stress-annealed at variable temperature is observed. Such microwires annealed with a temperature gradient also present a variable squareness ratio and magnetic anisotropy field along the microwire’s length. The obtained graded anisotropy has been attributed to a gradual modification of the domain structure along the microwire originated by a counterbalance between shape, magnetoelastic, and induced magnetic anisotropies. Accordingly, we propose a rather simple route to design graded magnetic anisotropy in a magnetic microwire.This work was funded by and by the EU under “INFINITE” (Horizon 2020) project, by the Spanish MCIU under PGC2018-099530-B-C31 (MCIU/AEI/FEDER, UE), by the Government of the Basque Country under PIBA 2018-44, PUE_2021_1_0009 and Elkartek (CEMAP and AVANSITE) projects, by the Diputación Foral de Gipuzkoa in the frame of Programa “Red guipuzcoana de Ciencia, Tecnología e Innovación 2021” under 2021-CIEN-000007-01 project and by the University of Basque Country under the scheme of “Ayuda a Grupos Consolidados” (Ref.: GIU18/192) and COLAB20/15 project

Tuning of Magnetoimpedance Effect and Magnetic Properties of Fe-Rich Glass-Coated Microwires by Joule Heating

The influence of Joule heating on magnetic properties, giant magnetoimpedance (GMI) effect and domain wall (DW) dynamics of Fe75B9Si12C4 glass-coated microwires was studied. A remarkable (up to an order of magnitude) increase in GMI ratio is observed in Joule heated samples in the frequency range from 10 MHz to 1 GHz. In particular, an increase in GMI ratio, from 10% up to 140% at 200 MHz is observed in Joule heated samples. Hysteresis loops of annealed samples maintain a rectangular shape, while a slight decrease in coercivity from 93 A/m to 77 A/m, after treatment, is observed. On the other hand, a modification of MOKE hysteresis loops is observed upon Joule heating. Additionally, an improvement in DW dynamics after Joule heating is documented, achieving DW propagation velocities of up to 700 m/s. GMI ratio improvement along with the change in MOKE loops and DW dynamics improvement have been discussed considering magnetic anisotropy induced by Oersted magnetic fields in the surface layer during Joule heating and internal stress relaxation. A substantial GMI ratio improvement observed in Fe-rich Joule-heated microwires with a rectangular hysteresis loop and fast DW propagation, together with the fact that Fe is a more common and less expensive metal than Co, make them suitable for use in magnetic sensors.This work was funded by the Spanish MCIU under PGC2018-099530-B-C31 (MCIU/AEI/FEDER, UE), by the EU under “INFINITE” (Horizon 2020) project, by the Government of the Basque Country under PUE_2021_1_0009 and Elkartek (CEMAP and AVANSITE) projects by the Diputación Foral de Gipuzkoa in the frame of Programa “Red guipuzcoana de Ciencia, Tecnología e Innovación 2021” under 2021-CIEN-000007-01 project and by the University of Basque Country under the scheme of “Ayuda a Grupos Consolidados” (Ref.: GIU18/192) and COLAB20/15 project

Development of magnetically soft amorphous microwires for technological applications

ABSTRACT: Amorphous magnetic microwires can be suitable for a variety of technological applications due to their excellent magnetic softness and giant magnetoimpedance (GMI) effect. Several approaches for optimization of soft magnetic properties and GMI effect of magnetic microwires covered with an insulating, flexible, and biocompatible glass coating with tunable magnetic properties are overviewed. The high GMI effect and soft magnetic properties, achieved even in as-prepared Co-rich microwires with a vanishing magnetostriction coefficient, can be further improved by appropriate heat treatment (including stress-annealing and Joule heating). Although as-prepared Fe-rich amorphous microwires exhibit low GMI ratio and rectangular hysteresis loops, stress-annealing, Joule heating, and combined stress-annealed followed by conventional furnace annealing can substantially improve the GMI effect (by more than an order of magnitude).This work was funded by Spanish MCIU under PGC2018-099530-B-C31 (MCIU/AEI/FEDER, UE), by EU under “INFINITE”(Horizon 2020) project, by the Government of the Basque Country, under PIBA 2018-44, PUE_2021_1_0009, and Elkartek (CEMAP and AVANSITE) projects, by the Diputación Foral de Gipuzkoa in the frame of Programa “Red guipuzcoana de Ciencia, Tecnología e Innovación 2021” under 2021-CIEN-000007-01 project and by the University of Basque Country, under the COLAB20/15 project

Optimization of Magnetoimpedance Effect and Magnetic Properties of Fe-Rich Glass-Coated Microwires by Annealing

As-prepared Fe-rich microwires with perfectly rectangular hysteresis loops present magnetization reversal through fast domain wall propagation, while the giant magnetoimpedance (GMI) effect in Fe-rich microwires is rather low. However, the lower cost of Fe-rich microwires makes them attractive for magnetic sensors applications. We studied the effect of conventional (furnace) annealing and Joule heating on magnetic-propertied domain wall (DW) dynamics and the GMI effect in two Fe microwires with different geometries. We observed that magnetic softness, GMI effect and domain wall (DW) dynamics can be substantially improved by appropriate annealing. Observed experimental results are discussed considering the counterbalance between the internal stresses relaxation and induced magnetic anisotropy associated with the presence of an Oersted magnetic field during Joule heating.This work was funded by the Spanish MICIN under PID2022-141373NB-I00, by the EU “Horizon Europe “under the “INFINITE” (HORIZON-CL5-2021-D5-01-06) project and by the government of the Basque Country under PUE_2021_1_0009, “Ayuda a Grupos Consolidados” (ref. IT1670-22) and Elkartek (MINERVA, MAGAF and ZE-KONP) projects

Anomalous Magnetic Anisotropy Behaviour in Co-Rich and Fe-Rich Glass-Coated Microwires under Applied Stress

In this article, we study the effect of annealing temperature and applied stress on the magnetic properties of Fe71.80B13.27Si11.02Nb2.99Ni0.92 and Co65.34Si12.00B10.20Cr8.48Fe3.90Mo0.08 microwires. An anomalous behavior of the coercive field is observed while applying stress, indicating nontrivial changes in the microwire magnetic anisotropy. The effect of applied stimuli on the magnetic anisotropy and magnetostriction constant in both microwires is also discussed.This work was supported by the EU under the “INFINITE” (HORIZON-CL5-2021-D5-01-06) project by the Spanish MICIN (PID2022-141373NB-I00) project as well as the Government of the Basque Country (PUE-2021-1-0009), Elkartek (MINERVA, MAGAF and ZE-KONP) projects and under the scheme of “Ayuda a Grupos Consolidados” (ref. IT1670-22)

Afectación del derecho a la libertad por el juez de control de garantías

El aparato jurisdiccional en Colombia, particularmente en el ámbito penal se ha caracterizado entre otras cosas por la demora en los trámites judiciales, para el respectivo impulso procesal, en su mayoría de los casos, por el ente acusatorio es decir La Fiscalía General de la Nación, con sus respectivos delegados, así como los altos índices de violación a derechos y garantías constitucionales y legales según informe de audiencia pública de rendición de cuentas por parte de la fiscalía en los años 2009 y 2010, del que han dado en más de una oportunidad la viabilidad para demandar al Estado por los daños y perjuicios ocasionados a los particulares como consecuencia de los errores cometidos por los funcionarios pertenecientes a la rama judicial del poder público

Genetic analysis of high bone mass cases from the BARCOS cohort of spanish postmenopausal women

The aims of the study were to establish the prevalence of high bone mass (HBM) in a cohort of Spanish postmenopausal women (BARCOS) and to assess the contribution of LRP5 and DKK1 mutations and of common bone mineral density (BMD) variants to a HBM phenotype. Furthermore, we describe the expression of several osteoblast-specific and Wnt-pathway genes in primary osteoblasts from two HBM cases. A 0.6% of individuals (10/1600) displayed Z-scores in the HBM range (sum Z-score >4). While no mutation in the relevant exons of LRP5 was detected, a rare missense change in DKK1 was found (p.Y74F), which cosegregated with the phenotype in a small pedigree. Fifty-five BMD SNPs from Estrada et al. [NatGenet 44:491-501,2012] were genotyped in the HBM cases to obtain risk scores for each individual. In this small group of samples, Z-scores were found inversely related to risk scores, suggestive of a polygenic etiology. There was a single exception, which may be explained by a rare penetrant genetic variant, counterbalancing the additive effect of the risk alleles. The expression analysis in primary osteoblasts from two HBM cases and five controls suggested that IL6R, DLX3, TWIST1 and PPARG are negatively related to Z-score. One HBM case presented with high levels of RUNX2, while the other displayed very low SOX6. In conclusion, we provide evidence of lack of LRP5 mutations and of a putative HBM-causing mutation in DKK1. Additionally, we present SNP genotyping and expression results that suggest additive effects of several genes for HBM

Valorización de la acción de Unión Andina de Cementos en el contexto de pandemia por COVID-19

La empresa Unión Andina de Cementos (UNACEM) nace en el año 2012 y es producto de la fusión de Cementos Lima S.A.A. y Cemento Andino S.A. Está dedicada al procesamiento, producción, comercialización y exportación de cemento y clínker. Mantiene una cuota de mercado del 46% aproximadamente y es la empresa de cemento más importante del Perú. Sus principales accionistas son Inversiones JRPR S.A (25.08%) y Nuevas Inversiones S.A. (25.25%), ambas propiedades de la familia Rizo Patrón. UNACEM cuenta con dos plantas de cemento en el Perú: la Planta Atocongo en Lima y la Planta Condorcocha en Tarma, Junín, además de dos empresas eléctricas, CELEPSA –El Platanal en la cuenca del río Cañete en Yauyos, y Carpapata en Tarma, Junín. Adicionalmente cuenta con una red de agentes denominada Progre-Sol con más de 800 ferreterías que actúan como distribuidores autorizados en el canal minorista. La empresa posee un gran poder de negociación, tanto por su integración vertical -desde yacimientos propios hasta muelle de exportación- como por su oligopolio comercial en la parte central del Perú. Además, cuenta con planes de responsabilidad social y ejecuta planes de desarrollo social y ambiental en las zonas de influencia a sus partes relacionadas. El equipo consultor de CENTRUM ha recibido el encargo de establecer el valor de la capitalización bursátil de UNACEM y determinar el valor de la acción al 31 de diciembre del 2019 mediante el método de valorización más adecuado. La presente investigación se realizó utilizando información de UNACEM únicamente de fuentes públicas: La Superintendencia de Mercado de Valores, la Bolsa de Valores de Lima, Memorias Anuales, Reportes de Sostenibilidad y Estados Financieros. Además, se entrevistó al Mag. Francisco Barúa Costa, Gerente de Inversiones de UNACEM quien nos permitió comprender mejor la industria cementera. Esta investigación determinó que la metodología más idónea para estimar el valor intrínseco de UNACEM es el método de valorización por flujo de caja libre descontado con un horizonte de proyección de diez años a una tasa de descuento WACC de 8.754% y con una tasa de perpetuidad del 1%. Posteriormente a la aplicación de la metodología y tomando en consideración los efectos económicos de la pandemia originada por el COVID-19 en el corto, mediano y largo plazo, este valor se estimó en S/1.51 por acción. Con ese resultado y teniendo en cuenta las fortalezas y potencialidades de la empresa estudiada, la recomendación del equipo consultor es comprar acciones de UNACEM, ya que, a pesar de que el precio refleja la disminución de los flujos de caja por menores ventas en el contexto de la pandemia, la acción de la empresa tiene un gran potencial de apreciación en el mediano y largo plazo.The company Unión Andina de Cementos (UNACEM) was established in 2012 from the merger of Cementos Lima S.A.A. and Cemento Andino S.A. UNACEM is dedicated to the processing, production, marketing and export of cement and clinker. With an important market share gained of approximately 46%, it is one of the most important cement companies in Perú. Its majority shareholders are Inversiones JRPR S.A (25.08%) and Nuevas Inversiones S.A (25.25%), both owned by the Rizo Patron family. UNACEM has two cement plants in Peru: the Atocongo Plant in Lima and the Condorcocha Plant in Tarma, Junín, as well as two hydroelectric power stations: CELEPSA - El Platanal in the basin of Cañete River in Yauyos, and Carpapata in Tarma, Junín. Additionally, has a network of agents called Progre-Sol with more than 800 hardware stores that act as authorized distributors in the retail channel. The company has a strong negotiating position, both for its vertical integration -from its own reserves or its export dock- and for its commercial oligopoly in the central sierra of Peru. In addition, has concrete plans to strengthen corporate social responsibility and executes social and environmental development plans in the areas of influence to its stakeholders. The CENTRUM consulting team has been commissioned to establish the value of UNACEM's market capitalization and determine the value of its share at December 31, 2019 using the most appropriate valuation method. This research was carried out using information from open sources about UNACEM: Superintendencia de Mercado de Valores, Bolsa de Valores de Lima, Annual Reports, Sustainability Reports and Financial Statements. In addition, Mag. Francisco Barúa Costa, Chief Investment Officer & Investment Manager at UNACEM, was interviewed, who was able to provide a better understanding about cement industry. This research determined that the most suitable valuation methodology to estimate the intrinsic value of UNACEM is the discounted free cash flow method with a forecasting horizon of ten years using a WACC discount rate of 8.754% and with a perpetuity rate of 1%. After applying this methodology and considering the economic effects of the pandemic caused by COVID-19 in the short, medium and long term, this value was estimated at S/1.51 per share. With this result and taking into account the strengths and potential of the evaluated company, the recommendation of the consulting team is to buy shares of UNACEM, by reason of, despite the price reflects a decrease in cash flows caused by lower sales, in the context of the pandemic, the company's share has great potential for appreciation in the medium and long term

Controlling of the single domain wall propagation in magnetic microwires by magnetostatic interaction

Ultrafast magnetization switching through the single domain wall (DW) propagation has been reported in amorphous micrometric and submicrometric wires. However the performance of prospective devices utilizing DW propagation is determined by the degree to which DW propagation can be controlled. In this article, we propose a novel method for effectively controlling the single DW propagation in a specially designed array consisting of two magnetic microwires by the stray field from magnetically softer microwires. We have experimentally demonstrated that the DW velocity of magnetically harder Fe-rich microwire in such a linear array is affected by the stray field of magnetically softer Co-rich microwire. Additionally, the domain wall can be trapped in the Fe-rich microwire by the stray field produced by the Co-rich microwire in such a linear array. The observed effect of magnetostatic interaction depends on the position of the Co-rich microwire in such a linear array. Controllable domain wall propagation observed in such a linear array can be a useful tool for simple and more flexible ways of controllable trapping and braking of single DWs in Fe-rich microwires showing spontaneous magnetic bistability.This work was supported by EU (Horizon Europe) under “INFINITE” (HORIZON-CL5-2021-D5-01-06) and “Harmony” (HORIZON-CL4-2023-RESILIENCE-01) projects, by the Spanish MICIN, under PID2022-141373NB-I00 project and by the Government of the Basque Country under Elkartek (MOSINCO) project and under the scheme of “Ayuda a Grupos Consolidados” (ref. IT1670-22). The authors thank for technical and human support provided by SGIker of UPV/EHU (Medidas Magneticas Gipuzkoa) and European funding (ERDF and ESF). The authors wish to acknowledge useful discussions with Prof. A. Fert