Exact aymptotic expansions for the thermodynamics of hydrogen gas in the Saha regime

We consider the hydrogen quantum plasma in the Saha regime, where it almost reduces to a partially ionized atomic gas. We briefly review the construction of systematic expansions of thermodynamical functions beyond Saha theory, which describes an ideal mixture of ionized protons, ionized electrons and hydrogen atoms in their ground-state. Thanks to the existence of rigorous results, we first identify the simultaneous low-temperature and low-density limit in which Saha theory becomes asymptotically exact. Then, we argue that the screened cluster representation is well suited for calculating corrections, since that formalism accounts for all screening and recombination phenomena at work in a more tractable way than other many-body methods. We sketch the corresponding diagrammatical analysis, which leads to an exact asymptotic expansion for the equation of state. That scaled low-temperature expansion improves the analytical knowledge of the phase diagram. It also provides reliable numerical values over a rather wide range of temperatures and densities, as confirmed by comparisons to quantum Monte Carlo data.Comment: 10 page

On the Static Dielectric Permittivity for Coulomb System in the Long Wavelength Limit

On the basis of the exact relations the general formula for the static dielectric permittivity for Coulomb system is found in the region of small wave vectors. The obtained formula describes the dielectric function of the Coulomb system in both limits: in the "metallic" state and in the "dielectric" one. On this basis the determinations of the "apparent" dielectric and the "apparent" radius of screening are introduced. In the random phase approximation (RPA) the exact relations for the function dielectric function of the electron gas in the long-wavelength region of the wave vectors are found for an arbitrary degeneration of the particles.Comment: 5 pages, no figure

Co-doping effect on the microstructural and electrical properties of barium stannate materials

Proton-conducting perovskite oxides are of considerable interest to researchers as promising electrolytes for low- and intermediate solid oxide electrochemical cells. Therefore, designing new potential proton-conducting phases and improving the functional properties of known materials are of great importance from both fundamental and applied viewpoints. In the present work, BaSnO3 was selected as a reference proton-conducting system and then a co-doping strategy was employed to analyze ‘composition – structure – microstructure – transport properties’ relationships. To perform such an analysis, the properties of previously studied BaSn0.7M0.3O3–δ (M = In, Sc, Y) compounds were compared here to their co-doped derivatives, BaSn0.7In0.15Sc0.15O3–δ, BaSn0.7Y0.15Sc0.15O3–δ, and BaSn0.7In0.15Y0.15O3–δ. It is found that the type of dopant affects the materials sinterability, when more coarse-crystalline ceramics are formed with increasing the average ionic radii at the Sn-position. The introduction of Y3+-cations reduces both ionic and hole conductivities compared to single-doped with In3+ or Sc3+ barium stannate materials. However, simultaneous doping with In3+/Sc3+ cations minimizes the contribution of hole conductivity compared to that of Sc-doped barium stannate with the same acceptor dopant concentration.https://doi.org/10.15826/elmattech.2024.3.03

Equation of state SAHA-S meets stellar evolution code CESAM2k

We present an example of an interpolation code of the SAHA-S equation of state that has been adapted for use in the stellar evolution code CESAM2k. The aim is to provide the necessary data and numerical procedures for its implementation in a stellar code. A technical problem is the discrepancy between the sets of thermodynamic quantities provided by the SAHA-S equation of state and those necessary in the CESAM2k computations. Moreover, the independent variables in a practical equation of state (like SAHA-S) are temperature and density, whereas for modelling calculations the variables temperature and pressure are preferable. Specifically for the CESAM2k code, some additional quantities and their derivatives must be provided. To provide the bridge between the equation of state and stellar modelling, we prepare auxiliary tables of the quantities that are demanded in CESAM2k. Then we use cubic spline interpolation to provide both smoothness and a good approximation of the necessary derivatives. Using the B-form of spline representation provides us with an efficient algorithm for three-dimensional interpolation. The table of B-spline coefficients provided can be directly used during stellar model calculations together with the module of cubic spline interpolation. This implementation of the SAHA-S equation of state in the CESAM2k stellar structure and evolution code has been tested on a solar model evolved to the present. A comparison with other equations of state is briefly discussed. The choice of a regular net of mesh points for specific primary quantities in the SAHA-S equation of state, together with accurate and consistently smooth tabulated values, provides an effective algorithm of interpolation in modelling calculations. The proposed module of interpolation procedures can be easily adopted in other evolution codes.Comment: 8 pages, 5 figure

Роль ультразвука в диагностике внебольничной пневмонии

BACKGROUND The literature review is devoted to an urgent problem of the diagnosis of pneumonia in the practice of an anesthesiologist-resuscitator using ultrasound. The literature review describes the methodological foundations of this method, its advantages and disadvantages, sensitivity and specificity for the diagnosis of severe community-acquired pneumonia in the practice of an anesthesiologist-resuscitator.AIM OF STUDY The analysis of the most modern domestic and foreign evidence base based on the information content of lung ultrasound in CAP in the practice of an anesthesiologist-resuscitator.MATERIAL AND METHODS Russian publications were searched in the elibrary.ru database, foreign publications were searched in the PubMed database. Publications (literature reviews, observational studies, double-blind randomized trials) were searched for the period 2010–2020. A total of 1379 publications were initially selected, identified through database searches. After removing duplicates, the number of publications was reduced to 695. Of this number, 503 publications were excluded. The remaining 192 full-text articles were evaluated for text acceptability. Due to inconsistency with the main sections of the review, 77 articles were deleted from them. The remaining 115 ones were included in the qualitative synthesis and 67 ones were selected in the quantitative synthesis.RESULTS The ultrasound is a promising and worthy alternative to other imaging modalities. According to the results chest X-ray was inferior to lung ultrasound in diagnosing the presence of fluid in the pleural cavities. The sensitivity of ultrasound in assessing pleural effusion reaches 100%, the specificity is 99.7%. Pulmonary ultrasonography plays an important role in the diagnosis of pneumonia and is a promising alternative to chest X-ray and chest CT.DISCUSSION Since POCUS is performed at the patient’s bedside, the results are available to the doctor in real time, which helps in diagnosis and treatment. Sequential examinations can be performed to monitor disease progression and response to treatment. However, many facilities do not have the ability to store ultrasound images, so other healthcare professionals cannot see them.FINDINGS The ultrasound examination of the lungs is unlikely to replace computed tomography of the chest, as it does not have 100% specificity, however, it is indispensable in bedside examination and is the doctor’s sonographic “stethoscope”, which significantly expands diagnostic capabilities.АКТУАЛЬНОСТЬ Обзор литературы посвящен актуальной проблеме — диагностике пневмонии с помощью ультразвука. В обзоре описаны методические основы данного метода, его преимущества и недостатки, чувствительность и специфичность для диагностики тяжелой внебольничной пневмонии в практике врача анестезиолога-реаниматолога.ЦЕЛЬ Анализ информативности ультразвукового исследования (УЗИ) легких при внебольничной пневмонии в современной отечественной и зарубежной доказательной базе врача анестезиологареаниматолога.МАТЕРИАЛ И МЕТОДЫ Поиск отечественных публикаций проводили в базе данных eLibrary.ru, зарубежных — в базе данных PubMed. Был проведен поиск по публикациям (обзоры литературы, обсервационные исследования, двойные слепые рандомизированные исследования) за период 2010–2020 гг. Первично было выбрано 1379 публикаций, идентифицированных через поиск баз данных. После удаления повторов количество публикаций сократилось до 695. Из этого числа исключили 503 публикации. Оставшиеся 192 полнотекстовые статьи оценивались на приемлемость текста. По причине несоответствия основным разделам обзора из них было удалено 77 статей. Остальные 115 были включены в качественный синтез и 67 избраны в количественный синтез.РЕЗУЛЬТАТЫ Ультразвук является многообещающей и достойной альтернативой другим методам лучевой диагностики. По результатам анализа рентгенография органов грудной клетки (Rg ОГК) уступила УЗИ легких в диагностике наличия жидкости в плевральных полостях. Чувствительность УЗИ при оценке плеврального выпота достигает 100%, специфичность — 99,7%. УЗИ легких играет важную роль в диагностике пневмонии и является многообещающей привлекательной альтернативой Rg ОГК и компьютерной томографии ОГК.ОБСУЖДЕНИЕ Поскольку УЗИ в месте оказания медицинской помощи (POCUS) выполняется у постели больного, результаты доступны врачу в режиме реального времени, что помогает в диагностике и выборе тактики лечения. Последовательные серии УЗИ могут быть выполнены для мониторинга динамики заболевания и реакции на лечение. Однако во многих учреждениях нет возможности сохранять УЗ-изображения, поэтому другие медицинские работники не могут их видеть.ВЫВОДЫ Ультразвуковое исследование легких вряд ли сможет заменить компьютерную томографию органов грудной клетки, так как не обладает 100% специфичностью, однако оно незаменимо в прикроватном исследовании и является сонографическим «стетоскопом» врача, который значительно расширяет диагностические возможности

Germanium Detector with Internal Amplification for Investigation of Rare Processes

Device of new type is suggested - germanium detector with internal amplification. Such detector having effective threshold about 10 eV opens up fresh opportunity for investigation of dark matter, measurement of neutrino magnetic moment, of neutrino coherent scattering at nuclei and for study of solar neutrino problem. Construction of germanium detector with internal amplification and perspectives of its use are described.Comment: 13 pages, latex, 3 figures, report at NANP-99, International Conference on Non-Accelerator Physics, Dubna, Russia, June 29- July 3, 1999. To be published in the Proceeding

Electrophoretic deposition of YSZ layers on pyrolytic graphite and a porous anode substrate based on NiO-YSZ

Solid oxide fuel cells are promising hydrogen energy devices. The goal of this research was to create ceramic layers for SOFCs based on yttria-stabilized zirconia (YSZ) and to investigate their parameters. YSZ ceramic layers with a thickness of 5.14 μm on a porous NiO–YSZ substrate and 7 μm on pyrolytic graphite were obtained by electrophoretic deposition. X-ray diffraction and electron microscopy were used to determine the composition, structure, and morphological features of ceramic layers. The effects of the substrate's nature, the degree of dispersion of the initial YSZ powder, and the heat treatment conditions on the properties of the ceramic layer YSZ were considered

GEMMA experiment: three years of the search for the neutrino magnetic moment

The result of the 3-year neutrino magnetic moment measurement at the Kalinin Nuclear Power Plant with the GEMMA spectrometer is presented. Antineutrino-electron scattering is investigated. A high-purity germanium detector of 1.5 kg placed at a distance of 13.9 m from the 3 GW(th) reactor core is used in the spectrometer. The antineutrino flux is 2.7E13 1/scm/s. The differential method is used to extract (nu-e) electromagnetic scattering events. The scattered electron spectra taken in 5184+6798 and 1853+1021 hours for the reactor ON and OFF periods are compared. The upper limit for the neutrino magnetic moment < 3.2E-11 Bohr magneton at 90% CL is derived from the data processing.Comment: 4 pages, 4 figure