Astrophysical line diagnosis requires non-linear dynamical atomic modeling

Line intensities and oscillator strengths for the controversial 3C and 3D astrophysically relevant lines in neonlike Fe${}^{16+}$ ions are calculated. We show that, for strong x-ray sources, the modeling of the spectral lines by a peak with an area proportional to the oscillator strength is not sufficient and non-linear dynamical effects have to be taken into account. Furthermore, a large-scale configuration-interaction calculation of oscillator strengths is performed with the inclusion of higher-order electron-correlation effects. The dynamical effects give a possible resolution of discrepancies of theory and experiment found by recent measurements, which motivates the use of light-matter interaction models also valid for strong light fields in the analysis and interpretation of astrophysical and laboratory spectra.Comment: 5 pages, 3 figure

QED calculation of the 2p1/2-2s and 2p3/2-2s transition energies and the ground-state hyperfine splitting in lithiumlike scandium

We present the most accurate up-to-date theoretical values of the {2p_{1/2}}-{2s} and {2p_{3/2}}-{2s} transition energies and the ground-state hyperfine splitting in ${\rm Sc}^{18+}$. All two- and three-electron contributions to the energy values up to the two-photon level are treated in the framework of bound-state QED without \aZ-expansion. The interelectronic interaction beyond the two-photon level is taken into account by means of the large-scale configuration-interaction Dirac-Fock-Sturm (CI-DFS) method. The relativistic recoil correction is calculated with many-electron wave functions in order to take into account the electron-correlation effect. The accuracy of the transition energy values is improved by a factor of five compared to the previous calculations. The CI-DFS calculation of interelectronic-interaction effects and the evaluation of the QED correction in an effective screening potential provide significant improvement for the $2s$ hyperfine splitting. The results obtained are in a good agreement with recently published experimental data.Comment: 10 pages, 2 table

Ground-state hyperfine structure of H-, Li-, and B-like ions in middle-Z region

The hyperfine splitting of the ground state of H-, Li-, and B-like ions is investigated in details within the range of nuclear numbers Z = 7-28. The rigorous QED approach together with the large-scale configuration-interaction Dirac-Fock-Sturm method are employed for the evaluation of the interelectronic-interaction contributions of first and higher orders in 1/Z. The screened QED corrections are evaluated to all orders in (\alpha Z) utilizing an effective potential approach. The influence of nuclear magnetization distribution is taken into account within the single-particle nuclear model. The specific differences between the hyperfine-structure level shifts of H- and Li-like ions, where the uncertainties associated with the nuclear structure corrections are significantly reduced, are also calculated.Comment: 22 pages, 11 tables, 2 figure

Relativistic recoil, electron-correlation, and QED effects on the 2p_j-2s transition energies in Li-like ions

The relativistic nuclear recoil, higher-order interelectronic-interaction, and screened QED corrections to the transition energies in Li-like ions are evaluated. The calculation of the relativistic recoil effect is performed to all orders in 1/Z. The interelectronic-interaction correction to the transition energies beyond the two-photon exchange level is evaluated to all orders in 1/Z within the Breit approximation. The evaluation is carried out employing the large-scale configuration-interaction Dirac-Fock-Sturm method. The rigorous calculation of the complete gauge invariant sets of the screened self-energy and vacuum-polarization diagrams is performed utilizing a local screening potential as the zeroth-order approximation. The theoretical predictions for the 2p_j-2s transition energies are compiled and compared with available experimental data in the range of the nuclear charge number Z=10-60.Comment: 39 pages, 3 figures, 11 table

Positive and negative properties of four endodontic sealant groups: a systematic review

Background. The choice of sealant is an important dentist’s decision with a long-term influence on treatment. Knowledge of the properties and characters of each material is key to the optimal endosealer selection on individual basis.Objectives. A comparison of endodontic sealants based on epoxy resins, calcium hydroxide, zinc oxide eugenol and bioceramics.Methods. Publications were mined in the PubMed and Google Scholar electronic databases to cover the four sealer groups (epoxy, calcium hydroxide, zinc oxide eugenol and bioceramics) over years 2014-2021, including selected relevant sources within 2002-2013; 73 articles were considered for review, regardless of the study design or language. Content and descriptive analyses were used as research tools. Meta-analysis was not used due to a high evidence heterogeneity.Results. The dental market currently offers a variety of sealant groups. Endodontic sealants based on epoxy resins, zinc oxide eugenol, calcium hydroxide and bioceramics are the most common. The review identifies no ideal material for the root canal filling.Conclusion. Manifold studies demonstrate the pros and cons in each endodontic sealant group with respect to variant criteria. Depending on clinical situation, the practitioner can opt for the material property to identify the endosealer

MAPPING NEWLY INUNDATED AREAS IN POST-FLOOD LANDSAT IMAGES USING THRESHOLDING TECHNIQUES

Identifying newly inundated areas following flood events is essential for planning rescue missions. These maps must be generated quickly as the spatial extent of the inundated areas might change during a single flood event. Several methods exist for generating such maps and several rely on one or more geospatial data to exclude existing waterbodies in an affected area. In this study, we tested a rapid flood mapping method that uses a pair of pre- and post-flood satellite images on seven sites throughout the US. We derived Normalized Difference Water Index (NDWI) and Modified NDWI (MNDWI) images from pre- and post-flood Landsat images and identified the optimal threshold values that highlighted newly inundated areas at these sites. The accuracy of the inundation maps was determined using manually interpreted verification data from the pairs of satellite images. Image analysts have identified the optimal threshold values between 25 and 40 minutes. Maps of newly inundated areas derived from differencing MNDWI and NDWI images had higher overall accuracy > 93%. Results obtained in this study confirms the utility of this rapid flood mapping technique to identify inundated areas using pre- and post-flood satellite images

Managing the Development of University Teachers’ Digital Pedagogical Competencies in Theory and in Practice

Статья посвящена вопросам развития цифровых педагогических компетенций преподавателей высших учебных заведений. Предложена концепция формирования команды цифровой трансформации вуза с учетом сложившейся в высшем образовании ситуации неопределенности, быстрой смены платформ и сервисов, растущей динамики изменений и появления новых знаний в области цифровой дидактики. Для удовлетворения спроса на высококачественные образовательные продукты требуются специальные организационные решения, в том числе создание педагогических команд. Целью статьи является разработка модели оценки индивидуальных и командных цифровых педагогических компетенций, которая позволяла бы принимать управленческие решения для ликвидации дефицита компетенций в команде на этапе проектирования образовательных продуктов и сервисов. В ходе исследования проанализированы существующие модели цифровых педагогических компетенций и сделан вывод о необходимости их сочетания с инструментами оценки индивидуальных и командных цифровых педагогических компетенций. Предлагается общая концепция программ повышения квалификации, основанная на предлагаемой модели, которая состоит из трех направлений оценки: техническое, педагогическое, предметное (научная отрасль, направление подготовки). На основе анализа реализации дистанционного обучения с применением цифровых образовательных ресурсов в Уральском федеральном университете даются рекомендации по повышению эффективности команд разработки и внедрению цифровых продуктов. Данная публикация будет интересна менеджерам системы высшего образования, а также ученым и педагогам, интересующимся вопросами цифровизации, цифровой дидактики, цифровой трансформации вузов и индивидуализации обучения.The article studies the development of higher educational institution teachers’ digital pedagogical competencies. Considering the current situation of uncertainty in higher education, the rapid change of digital platforms and services, the growing dynamics of changes and the emergence of new knowledge in the sphere of digital didactics, the authors propose a concept of forming a university digital transformation team. To meet the demand for high-quality digital educational products, there are required special organizational solutions, including the creation of pedagogical teams. The purpose of the article is to develop a model for assessing individual and team digital pedagogical competencies, which allows making managerial decisions and eliminating the lack of competencies in a team at the stage of designing digital educational products and services. The study analyzed the existing models of digital pedagogical competencies and drew the conclusion on the need to refine them with specific tools for assessing current individual and team digital pedagogical competencies for the development and implementation of an educational product or project. Based on the model proposed, the paper puts forward a general concept of a professional retraining program, which consists of three areas of assessment: technical, pedagogical, subject (area of research, direction of training). Based on the analysis of Ural Federal University’s experience of implementing distance learning using digital educational resources, the authors give recommendations on how to improve the efficiency of the development teams and the implementation of digital educational products. This publication might be of interest for managers of the higher education system, as well as for scholars and teachers interested in digitalization, digital didactics, digital transformation of universities and individualization of education

High-resolution Photo-excitation Measurements Exacerbate the Long-standing Fe XVII Emission Problem

We measured the L-shell soft X-ray fluorescence of Fe XVII ions in an electron beam ion trap following resonant photo-excitation using synchrotron radiation provided by the P04 beamline at PETRA III. Special attention is paid to two 2p-3d transitions, the 3C and 3D lines that are essential plasma diagnostics tools for astrophysics. Their resulting oscillator-strength ratio, f(3C)/f(3D) = 3.09(8)(6), is three times more accurate than previous results. The present ratio clearly departs by approximately 5-sigmas from the newest ab initio calculations but confirms previous laboratory measurements and astrophysical observations. A ten thousand-fold reduction in excitation-photon intensity and ten times higher spectral resolution allow us to exclude current explanations, reinstating a forty-year-old atomic-physics puzzle

Algorithm of Hepatitis B Vaccinal Prevention at Children with Acute Lymphoblastic Leukemia in Dynamics of Program Therapy

Purpose: To create the algorithm of hepatitis B vaccinal prevention at children with acute lymphoblastic leukemia. Materials and Methods: The data of 181 children with acute lymphoblastic leukemia, from which 99 patients received specific hepatitis B prevention with vaccine «Engerix B», have been investigated. The authors have assessed correlations between efficiency of offered vaccinal prevention and leuco/neutropenia degrees at patients in days of vaccinations. The analysis of hepatitis B infect level at stages of vaccination was carried out. Results: The algorithm of hepatitis B vaccinal prevention at children with acute lymphoblastic leukemia is offered