91 research outputs found

    Stark Widths of Na IV Spectral Lines

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    Sodium is a very important element for the research and analysis of astrophysical, laboratory, and technological plasmas, but neither theoretical nor experimental data on Stark broadening of Na IV spectral lines are present in the literature. Using the modified semiempirical method of Dimitrijević and Konjević, here Stark widths have been calculated for nine Na IV transitions. Na IV belongs to the oxygen isoelectronic sequence, and we have calculated Stark widths belonging to singlets, triplets, and quintuplets, as well as with different parent terms. This is used to discuss similarities within one transition array with different multiplicities and parent terms. Additionally, calculated widths will be implemented in the STARK-B database (http://stark-b.obspm.fr) which is also a part of the Virtual Atomic and Molecular Data Center (VAMDC—http://www.vamdc.org/

    Gas temperature determination in microwave discharges at atmospheric pressure by using different Optical Emission Spectroscopy techniques

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    Non-thermal plasmas sustained at atmospheric pressure are considered as a very promising technology for different purposes, in which the knowledge of the gas temperature is an important issue. In this paper, the gas temperatures of different argon microwave (2.45 GHz) plasma torches were determined by using different Optical Emission Spectroscopy techniques. Thus, they were estimated through the analysis of N2+(B-X) and OH(A-X) molecular spectra. On the other hand, a method based on the measurement of the van der Waals broadening of 588.99 nm Na I line was employed, and the temperatures obtained from it were compared to the rotational temperatures derived from N2+(B-X) and OH(A-X) rotational bands. A reasonable good agreement was found between the values of temperatures obtained by using the 588.99 nm Na I line and those obtained from N2+ rotational band

    Measuring the electron density in plasmas from the difference of Lorentzian part of the widths of two Balmer series hydrogen lines

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    We present an alternative optical emission spectroscopy method to measure the plasma electron density from the difference of widths of two Balmer series hydrogen lines (Hα and Hβ), especially convenient for non-thermal plasmas since with this method, there is no need to know either the gas temperature or the van der Waals contribution to the Lorentzian part of the line. In this paper it has been assumed that the part of full width at half maximum due to Stark broadening can be determined with the approximation of Lorentzian line shape. The method has been applied to the determination of the electron density in an argon microwave-induced plasma maintained at atmospheric pressure, and comparison with the results obtained using other diagnostic methods has been done

    Simple and analytical function for the Stark profile of the Hα line and its application to plasma characterization

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    The increasing application of plasma based technologies over a wide range of fields has led to the necessity of an optimal determination of the characteristic parameters of the plasma systems. Optical Emission Spectroscopy techniques have been proved as an excellent tool to that end. These techniques are based on the collection and analysis of the radiation coming from the plasma, being classified between molecular and atomic emission. Among atomic emission lines, Hydrogen Balmer series lines are the most measured. The Hβ line is usually the most employed one for plasma diagnosis but under some conditions, the Hβ line is not always detectable and only the Hα line can be detected. For these lines, it is well known that their shapes are the result of the convolution of three profile types: Lorentzians, Gaussians and Starks. But while the first two types present analytical functions, models explaining the Stark profile do not offer these. So, in this paper we propose an accurate analytical function for the Stark profile of the Hα line allowing improving the determination of characteristic parameters of plasma with respect to the methods traditionally used

    A simple and accurate analytical model of the Stark profile and its application to plasma characterization

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    Optical Emission Spectroscopy techniques are among the most employed to perform the characterization of laboratory plasmas. The analysis of the obtained data is based on the convolution of three different types of profiles: Lorentzians, Gaussians and Starks. While analytic expressions are available for the first two types, the Stark profile has been traditionally obtained through theoretical calculations using different models. In this paper, we propose is a simple and accurate analytical function that can be employed as approximation of a Stark profile. The application of this new model may simplify the analysis of plasmas

    Using the Pairs of Lines Broadened by Collisions with Neutral and Charged Particles for Gas Temperature Determination of Argon Non-Thermal Plasmas at Atmospheric Pressure

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    The spectroscopic method for gas temperature determination in argon non-thermal plasmas sustained at atmospheric pressure proposed recently by Spectrochimica Acta Part B 129 14 (2017)—based on collisional broadening measurements of selected pairs of argon atomic lines, has been applied to other pairs of argon atomic lines, and the discrepancies found in some of these results have been analyzed. For validation purposes, the values of the gas temperature obtained using the different pairs of lines have been compared with the rotational temperatures derived from the OH ro-vibrational bands, using the Boltzmann-plot techniqu

    Teaching innovation in the reception days of Secondary Education and High School students to the Department of Physics

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    Este proyecto ha tratado de incorporar la participación de alumnos del Grado de Física, en concreto de 4º curso, en una de las actividades que se realizan en el Departamento de Física, las “Jornadas de recepción de alumnado de E.S.O. y Bachillerato al Departamento de Física”. Esta actividad consiste en recibir alumnado de E.S.O. y Bachillerato en las instalaciones del Departamento de Física para darles a conocer el estado actual del Grado de Física y mostrarles los laboratorios. El objetivo de esta actividad es fomentar su interés por la Ciencia en general y la Física en particular. La participación de los alumnos del Grado de Física en esta actividad les ha permitido trabajar una gran diversidad de competencias asociadas al Grado, tanto competencias básicas como algunas específicas del Título y de las que se han denominado competencias de Universidad.This project is based on the participation of students of the Physics Degree, in particular those who were in the final year of their studies, in one of the divulgation activities developed in the Department of Physics, “Reception days of Secondary and High School Students to the Department of Physics”. In this activity, Secondary and High School students are welcomed to the facilities of the Department of Physics to be informed about the Degree of Physics and to show them the laboratories. The objective of this activity is to stimulate their interest in science in general and physics in particular. The participation of the students of the Physics Degree in this activity has allowed them to work on a great variety of competences associated with their studies, including basic competences, some of their Degree specific competences as well as those categorized as University competences

    Análisis de los costes asociados al seguimiento de pacientes con VIH que discontinúan el tratamiento antirretroviral por falta de eficacia o toxicidad inaceptable en España

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    [Abstract] Objective. To assess the use of resources and the costs associated with following up patients infected with the human immunodeficiency virus after discontinuation of an antiretroviral treatment and initiation of a new one due to a lack of effectiveness or unacceptable toxicity, as compared to the costs involved in the routine follow-up of patients on antiretroviral treatment, from the Spanish National Health System perspective. Method. The use of resources (clinical tests, medical visits, and hospital pharmacy visits) associated with following three profiles of patients infected with the human immunodeficiency virus (stable ones, those discontinuing an existing antiretroviral treatment and being switched to a new one due to a lack of effectiveness, and those discontinuing an existing antiretroviral treatment and being switched to a new one due to unacceptable toxicity) was identified, based on clinical practice guidelines and the findings of a multidisciplinary expert panel (n = 5). The experts agreed on the main adverse events leading to discontinuation, classifying them into gastrointestinal, renal, osseous, musculoskeletal, dermatological, hepatic, lipid profile-related, neuropsychiatric and sexual alterations. Unit costs were identified from official healthcare costs databases. The cost (€, 2020) of following up each patient profile was estimated, excluding the cost of the antiretroviral treatment itself, with a time horizon of two years. Results. The per-patient cost of following up stable patients over two years was estimated at €4,148 (tests: €2,293; visits: €1,855). Patient follow-up after discontinuation of an existing antiretroviral treatment and initiation of a different one due to a lack of effectiveness was estimated at €5,434 (tests: €2,777; visits: €2,657). The cost of follow-up after discontinuation of an existing regimen and initiation of a new one due to unacceptable toxicity varied according to the adverse event prompting the switch, ranging from €4,690 for lipid profile dysregulation, to €5,304, for musculoskeletal alterations. In this patient profile, the cost of tests ranged from €2,403 to €3,017, and that of visits from €2,287 to €2,842. Conclusions. The cost associated with following up of patients infected with the human immunodeficiency virus after discontinuation of an existing antiretroviral regimen and initiation of a new one is higher than that of routine follow-up, without taking the cost of drugs into account. The treatment discontinuation rate is a relevant factor when selecting the most appropriate therapy for each patient.[Resumen] Objetivo. Estimar el uso de recursos y costes asociados al seguimiento de pacientes con infección por el virus de la inmunodeficiencia humana tras discontinuación del tratamiento antirretroviral actual debido a falta de efectividad o toxicidad inaceptable y cambio a un nuevo tratamiento antirretroviral, comparado con el seguimiento habitual de los pacientes con tratamiento antirretroviral, desde la perspectiva del Sistema Nacional de Salud español. Método. Se identificó el uso de recursos (pruebas clínicas, visitas médicas, visitas a la farmacia hospitalaria) asociado al seguimiento de pacientes con infección por el virus de la inmunodeficiencia humana en tres perfiles de pacientes (estable, discontinuación y cambio por falta de efectividad, discontinuación y cambio por toxicidad inaceptable), a partir de las guías de práctica clínica y un panel de expertos multidisciplinar (n = 5). Los expertos consensuaron los principales eventos adversos que conducían a la discontinuación, agrupándolos en: alteraciones gastrointestinales, renales, óseas, musculoesqueléticas, dermatológicas, hepáticas y del perfil lipídico, trastornos neuropsiquiátricos y sexuales. Los costes unitarios se identificaron a partir de bases de datos oficiales de costes sanitarios y de la literatura. Se estimó el coste (€, 2020) del seguimiento en cada perfil de paciente, sin incluir el coste derivado del tratamiento antirretroviral, en un horizonte temporal de dos años. Resultados. El coste por paciente a dos años se estimó en 4.148 € (pruebas: 2.293 €; visitas: 1.855 €) para el seguimiento del paciente estable. El seguimiento del paciente tras discontinuación por falta de efectividad y cambio de tratamiento antirretroviral se estimó en 5.434 € (pruebas: 2.777 €; visitas: 2.657 €). El coste del seguimiento tras la discontinuación por toxicidad inaceptable y cambio de tratamiento antirretroviral varió en función del evento adverso que motivó el cambio, oscilando entre 4.690 € para las alteraciones del perfil lipídico, y 5.304 € para las alteraciones musculoesqueléticas. En este perfil de pacientes, las pruebas variaron entre 2.403 € y 3.017 € y las visitas entre 2.287 € y 2.842 €. Conclusiones. El coste asociado al seguimiento del paciente con infección por el virus de la inmunodeficiencia humana tras discontinuación y cambio a un nuevo tratamiento antirretroviral es mayor comparado con el seguimiento habitual, sin tener en cuenta el coste farmacológico. La tasa de discontinuación del tratamiento antirretroviral es un factor relevante a la hora de seleccionar la terapia más adecuada para cada paciente

    Development of Physics learning activities

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    La utilización de simulaciones y actividades que hacen uso de herramientas informáticas permite integrar los contenidos teóricos y prácticos en actividades atractivas para el alumno. Presentamos varias de estas actividades en asignaturas del grado de Física, pero que pueden adaptarse a asignaturas de otros grados. Se ha observado una mejora en las competencias en el uso de las TICs, así como una mejora en la comprensión de los fenómenos estudiados por parte de los alumnos.The use of simulations and activities including computing tools allows teaching activities integrating both the theoretical and practical aspects of a subject. Some examples are presented for subjects of the Physics Degree. We observed an improvement of the use of computing tools as also a better understanding of the physical phenomena described in these activities
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