Ab initio screening methodology applied to the search for new permanent magnetic materials

In this paper a computational high-throughput screening (HTS) approach to the search for alternative permanent magnetic materials is presented. Systems considered for a start are binary intermetallic compounds composed of rare-earth (RE) and transition metal (TM) elements. With the tight-binding-linear muffin-tin-orbital-atomic-sphere-approximation (TBLMTO-ASA) method of density functional theory (DFT) a variety of RE–TM intermetallic phases is investigated and their magnetic properties are obtained at rather low computational costs. Next, interstitial elements such as boron, carbon and nitrogen in these phases are considered. For promising candidate phases with high and stable spontaneous ferromagnetic polarization, the calculated local magnetic moments and exchange coupling parameters, as obtained from TB-LMTO-ASA calculations, are then used for Monte Carlo simulations to identify candidates with sufficiently high Curie temperatures (Tc). Finally, magnetocrystalline anisotropy constants (K1) of the most promising candidate phases are calculated with accurate, potential-shape-unrestricted DFT calculations using the Vienna ab initio simulation package. The computational HTS procedure is illustrated by results for a selection of hard-magnetic RE–TM phases like RETM5, RE2TM17 and RE2TM14B

Plan de Acción en España para la erradicación de la poliomelitis: Vigilancia de la Parálisis Flácida Aguda y Vigilancia de Enterovirus en España. Informe 2020

Centro Nacional de Epidemiología y Centro Nacional de Microbiología. ISCIII. Plan de acción en España para la Erradicación de la Poliomielitis. Vigilancia de la Parálisis Flácida Aguda y Vigilancia de Enterovirus en España, Informe año 2020. Madrid, 5 de noviembre de 2021.[ES] En España la situación libre de polio se monitoriza con la vigilancia de Parálisis Flácida Aguda (PFA) en niños menores de 15 años, como recomienda la Organización Mundial de la Salud (OMS). La vigilancia la realizan los servicios de vigilancia autonómicos y la red de laboratorios de PFA y a nivel nacional se coordina en el Centro Nacional de Epidemiología (CNE, ISCIII) y en el Laboratorio de Poliovirus del Centro Nacional de Microbiología (CNM, ISCIII). En el año 2020 en España no hubo casos de poliomielitis. Se notificaron 0,17 casos de PFA por 100.000 niños menores de 15 años, por debajo del objetivo de sensibilidad establecido por la OMS de un caso de PFA al año por cada 100.000 menores de 15 años. Solamente se detectaron enterovirus no-polio (EVNP) en las muestras de dos casos (EV-D68 y EV-B, respectivamente). En España también se realiza la vigilancia de EVNP en otros síndromes neurológicos para complementar el sistema de vigilancia de PFA. En las muestras investigadas en 2020 no se identificó ningún poliovirus y los EVNP más frecuentemente identificados fueron E-18, CV-A6 y E-21. Mientras haya circulación de poliovirus en el mundo hay que mantener activos los sistemas de vigilancia para detectar a tiempo cualquier importación de poliovirus. [EN] Spain monitors its polio-free status by conducting surveillance for cases of acute flaccid paralysis (AFP) in children less than 15 years of age, as recommended by the World Health Organization (WHO). The AFP surveillance is performed by the 19 Regional Epidemiological Surveillance Units and the AFP Surveillance Laboratory Network, coordinated at national level by the National Centre for Epidemiology (CNE. ISCIII) and the National Poliovirus Laboratory at Nacional Center of Microbiology (CNM. ISCIII) respectively. In 2020, no cases of poliomyelitis were reported from clinical surveillance; Spain reported 0.17 non-polio AFP cases per 100,000 children, below the WHO's performance criterion for a sensitive surveillance system (1 non-polio AFP cases per 100,000 children). The non-polio enteroviruses EV-D68, EV-B were identified from clinical specimens collected from AFP cases. Spain also performs enterovirus surveillance to complement the clinical system In 2020, non poliovirus were identified; The non-polioviruses E-18, CV-A6 y E-21 were the most frequently identified serotypes. As long as poliovirus is circulating in the world, surveillance systems must remain active to detect any importation of poliovirus in a timely manner.1. Resumen. 2. Introducción. 3. Resultados de la vigilancia de Parálisis Flácida Aguda (PFA) en España, 2020. 4. Resultados de la vigilancia de enterovirus, España 2020. 5. Resultados de la vigilancia medioambiental de poliovirus. España, 2020. 6. Sistema de Información Microbiológica (SIM). Meningitis por enterovirus. Tendencia. 7. Conclusiones.N

Annual Epidemiological Report: Acute Flaccid Paralysis Surveillance and Enterovirus Surveillance, Spain, 2019

Centro Nacional de Epidemiología y Centro Nacional de Microbiología. ISCIII. Plan de acción en España para la Erradicación de la Poliomielitis. Vigilancia de la Parálisis Flácida Aguda y Vigilancia de Enterovirus en España, año 2019. Madrid, 1 julio 2020.[ES]Los resultados de la vigilancia de parálisis flácida aguda (PFA) y de la vigilancia de enterovirus (EV) muestran que en España en el año 2019 no hubo casos de poliomielitis ni circulación de poliovirus. La sensibilidad del sistema está por debajo del objetivo establecido por la OMS–Europa de 1 caso de PFA al año por cada 100.000 menores de 15 años, al situarse en 0,55/104 hab (0,58/104 <15años en 2018 ). Sin embargo, su estudio una vez detectados es adecuado. El índice de vigilancia, que sintetiza la sensibilidad del sistema de vigilancia y su estudio en laboratorio, fue de 0,28, similar a otros años. Gracias a la vigilancia de EV se detectó un PV derivado de vacuna (PVDV) en un paciente excretor inmunodeprimido; además se hallaron diferentes EV-no polio, los serotipos identificados fundamentalmente fueron E-7, E-30, E-11, CV-A6 y E-13. En 2019 la OMS declaró la eliminación del PV salvaje tipo 3(PVS3) a nivel mundial, aunque resulta preocupante el aumento en la detección de PVS1 y PVDVc 2 tanto en muestras humanas como medioambientales. La Evaluación de la Comisión Regional de Certificación clasifica a España en 2018 como de riesgo bajo de transmisión de poliovirus. En Europa hay tres países con riesgo alto, debido fundamentalmente a la baja inmunidad de su población. Hay que mantener los sistemas ya establecidos de vigilancia de la circulación de EV -polio y no polio- (vigilancia de PFA, meningitis víricas y EV), de manera que permitan detectar a tiempo la circulación inesperada de un poliovirus o de otro tipo de EV clínicamente relevante. [EN]The results of acute flaccid paralysis (AFP) and enterovirus (EV) surveillance show that there were no cases of polio or poliovirus circulation in Spain in 2019. The sensitivity of the system is below the target set by WHO-Europe of 1 case of AFP per year per 100,000 children under 15 years, at 0.55/104 inhab (0.58/104 <15 years in 2018 ). However, their study once detected is adequate. The surveillance index, which synthesizes the sensitivity of the surveillance system and its laboratory study, was 0.28, similar to other years. Thanks to the surveillance of EV, a vaccine derived PV (PVDV) was detected in an immunosuppressed excretory patient; in addition, different non-polio-EV were found. The serotypes identified were mainly E-7, E-30, E-11, CV-A6 and E-13. In 2019 the WHO declared the elimination of wild PV type 3 (PVS3) worldwide, although the increase in detection of PVS1 and cVP2 in both human and environmental samples is of concern. The evaluation of the Regional Certification Commission classifies Spain in 2019 as having a low risk of poliovirus transmission. In Europe there are three countries at high risk, mainly due to the low immunity of their population. The already established systems for surveillance of the circulation of EV-polio and non-polio- (surveillance of AFP, viral meningitis and EV) must be maintained, so that the unexpected circulation of a poliovirus or other clinically relevant EV can be detected in time.N

CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

Diffusion and deactivation of As in Si: Combining atomistic and continuum simulation approaches

Possible arrangements of As in bulk Si have been investigated using ab initio calculations to establish the most stable configurations depending on As concentration and charge state. Consistently with these results we developed a continuous model for As activation and diffusion in Si. The model was implemented in the Sentaurus Process Simulator and calibrated using a wide range of experimental results available in the literature. It was independently tested for spike and flash annealing experiments with excellent results

Characterization of the pile-up of As at the SiO2/Si interface

The pile up of As at the SiO2/Si interface was investigated by grazing incidence X-ray fluorescence spectroscopy in combination with removal of silicon layers by etching with thicknesses on the order of a nanometer. In order to determine the thickness of the silicon layers removed at the interface, atomic force microscope measurements were performed at trench structures. With this method, it is possible to determine the thickness of the piled-up region in the silicon. In addition, it is possible to clearly distinguish between the segregated atoms and the As atoms in the bulk over a large range of implantation doses from 3e12 cm&#872 2;2 to 1E16 cm−2. The samples were annealed at 900 °C and 1000 °C, respectively, for times sufficiently long to ensure that the segregation reflects an equilibrium effect. With this approach, the pile-up of As was measured with new precision

Distribution and segregation of arsenic at the SiO2/Si interface

The segregation and pile-up of arsenic atoms at the Si/SiO2 interface in steady state was investigated in detail by a combination of gracing incidence x-ray flu orescence spectroscopy (GI-XRF) measurements, electrical measurements, etching o n the nanometer scale, and measurements of the step heights by interferometry. U sing GI-XRF measurements and removal of the highly doped segregation layer by a sensitive etching process it was possible to distinguish clearly between the pil ed-up atoms and the arsenic atoms in the bulk over a large range of implantation doses, from 3E12 to 1E16 cm−2. The samples were annealed at different tem peratures from 900 °C to 1200 °C for time periods long enough to make sure that the segregation reflects an equilibrium state. With additional step height measu rements at line-space structures, the thickness of the layer with the piled-up a rsenic and the shape of the segregation profile was determined. Electrical measu rements indicated that the segregated arsenic atoms are deep donors with an elec trical activity that increases eventually to full electrical activation for high sheet concentrations of the segregated atoms. The measured data can be modeled as a steady state of neutral arsenic atoms in the segregation layer with positiv ely charged substitutional arsenic atoms and free electrons. For the highest con centration, a saturation of the sheet concentration of segregated arsenic atoms was observed that correlates with the increase in electrical activation. For the use in process simulation programs, a three-phase segregation model was adapted and calibrated