Computational Strategy for Graphene: Insight from Odd Electrons Correlation

The correlation of odd electrons in graphene turns out to be significant so that the species should be attributed to correlated ones. This finding profoundly influences the computational strategy addressing it to multireference computational schemes. Owing to serious problems related to the schemes realization, a compromise can be suggested by using single-determinant approaches based on either Hartree-Fock or Density-Functional theory in the form of unrestricted open-shell presentation. Both computational schemes enable to fix the electron correlation, while only the Hartree-Fock theory suggests a set of quantities to be calculated that can quantitatively characterize the electron correlation and be used for a quantitative description of such graphene properties as magnetism, chemical reactivity, and mechanical response. The paper presents concepts and algorithms of the unrestricted Hartree-Fock theory applied for the consideration of magnetic properties of nanographenes, their chemical modification by the example of stepwise hydrogenation, as well as a possible governing the electron correlation by the carbon skeleton deformation.Comment: 17 pages, 11 figures, 3 table

Step-Wise Computational Synthesis of Fullerene C60 derivatives. 1.Fluorinated Fullerenes C60F2k

The reactions of fullerene C60 with atomic fluorine have been studied by unrestricted broken spin-symmetry Hartree-Fock (UBS HF) approach implemented in semiempirical codes based on AM1 technique. The calculations were focused on a sequential addition of fluorine atom to the fullerene cage following indication of the cage atom highest chemical susceptibility that is calculated at each step. The effectively-non-paired-electron concept of the fullerene atoms chemical susceptibility lays the foundation of the suggested computational synthesis. The obtained results are analyzed from energetic, symmetry, and the composition abundance viewpoints. A good fitting of the data to experimental findings proves a creative role of the suggested synthesis methodology.Comment: 33 pages, 11 figures, 2 tables, 2 chart

Эпидемиологическая и этиологическая характеристика внебольничной пневмонии у военнослужащихпо призыву в современный период. Сравнительная оценка эффективности пневмококковых вакцин.

The purpose of the study is to analyze morbidity and to determine etiology of community-acquired pneumonia of conscripts, to examine the epidemiological effectiveness of pneumococcal conjugate and non-conjugate polysaccharide vaccines for the prevention of community-acquired pneumonia in soldiers.Materials and methods. The incidence of communityacquired pneumonia of conscripts in the period from 2008 to 2017 was examined. PCR diagnosis of samples sputum and smears from the pharynx of 694 patients with pneumonia of conscripts was carried out to detect fragments of DNA/RNA of 14 different pathogens. Epidemiologic efficacy of conjugated and non-conjugated pneumococcal vaccine was studied in groups from a total population of 1727 soldiers.Results. It is established that over the past 8 years, the incidence of community-acquired pneumonia of military conscripts decreased by 2.7 times. However, the level of morbidity achieved in 2017 (25.7 ‰) is still very high compared to the incidence of contract soldiers (5.3 ‰) and the population (4.2 ‰).When determining the etiology of pneumonias in military conscripts by means of PCR diagnosis, the prevalence of S. pneumoniae and adenoviruses was established, the genetic material of which was detected in 56.3% and 35.9% of the examined samples, respectively. 56.1% of pneumonia had mixed, mainly viral-bacterial etiology.Among those who were vaccinated with pneumococcal conjugate vaccine, the incidence of community-acquired pneumonia was 4.5 times lower in the 5 – month follow – up period than in the comparison group (p < 0.001) (effectiveness was 77.7%), and among those who were vaccinated with non-conjugate polysaccharide vaccines it was 2.8 times lower (p < 0.001) (effectiveness was 64.3%).It was found that the use of pneumococcal conjugate vaccine in military teams formed a collective immunity that prevents the circulation of pneumococci and the development of diseases not only in vaccinated persons, but also in unvaccinated persons.Conclusion. Both types of pneumococcal vaccines – conjugate, first used in the military, and usually used non-conjugate polysaccharide vaccine, have shown high epidemiological effectiveness in the prevention of community-acquired pneumonia and can equally be recommended for vaccination of recruits a month before the call to military service and of young soldiers, not vaccinated before the call.Цель: анализ заболеваемости и определение этиологии внебольничной пневмонии военнослужащих по призыву в современный период, оценка эпидемиологической эффективности 13-валентной пневмококковой конъюгированной вакцины для профилактики внебольничной пневмонии в воинских коллективах в сравнении с эффективностью неконъюгированных пневмококковых полисахаридных вакцин.Материалы и методы: проанализированы заболеваемость внебольничной пневмонией военнослужащих по призыву в период с 2008 по 2017 г. и результаты ПЦРдиагностики проб мокроты и мазков из зева 694 больных пневмонией военнослужащих по обнаружению фрагментов ДНК/РНК 14 различных возбудителей. Проведена оценка эпидемиологической эффективности пневмококковых конъюгированной и неконъюгированных полисахаридных вакцин в группах военнослужащих общей численностью 1727 человек.Результаты: установлено, что за последние восемь лет заболеваемость внебольничными пневмониями военнослужащих по призыву снизилась в 2,7 раза. Однако достигнутый в 2017 г. уровень заболеваемости (25,7 ‰) все еще очень высок в сравнении с заболеваемостью военнослужащих по контракту (5,3 ‰) и населения (4,2 ‰).При определении этиологии пневмоний у военнослужащих по призыву с помощью ПЦР-диагностики установлено превалирование S. pneumoniae и аденовирусов, генетический материал которых был обнаружен в 56,3% и 35,9% обследованных проб соответственно. 56,1% пневмоний имели смешанную, в основном вирусно-бактериальную этиологию.Среди вакцинированных пневмококковой конъюгированной вакциной за 5-месячный период наблюдения заболеваемость внебольничной пневмонией была в 4,5 раза меньше, чем в группе сравнения (р < 0,001) (показатель эффективности составил 77,7%), а среди вакцинированных неконъюгированными полисахаридными вакцинами – в 2,8 раза меньше (р < 0,001) (показатель эффективности – 64,3%). Установлено, что при применении пневмококковой конъюгированной вакцины в коллективах военнослужащих формируется коллективный иммунитет, препятствующий циркуляции пневмококков и развитию заболеваний не только у привитых, но и у непривитых.Заключение: оба типа пневмококковых вакцин – конъюгированная, впервые примененная у военнослужащих, и обычно применяемая неконъюгированная полисахаридная вакцина – показали высокую эпидемиологическую эффективность в отношении профилактики внебольничных пневмоний и в равной степени могут быть рекомендованы для вакцинации призывников за месяц до призыва и новобранцев, не привитых перед призывом на военную службу

First Observation of Self-Amplified Spontaneous Emission in a Free-Electron Laser at 109 nm Wavelength

We present the first observation of Self-Amplified Spontaneous Emission (SASE) in a free-electron laser (FEL) in the Vacuum Ultraviolet regime at 109 nm wavelength (11 eV). The observed free-electron laser gain (approx. 3000) and the radiation characteristics, such as dependency on bunch charge, angular distribution, spectral width and intensity fluctuations all corroborate the existing models for SASE FELs.Comment: 6 pages including 6 figures; e-mail: [email protected]

Stretching and breaking of chemical bonds, correlation of electrons, and radical properties of covalent species

Chemical bonds are considered in light of correlation of valence electrons that is strengthened when the bond is dissociated. In the framework of the unrestricted Hartree-Fock single-reference version of the configuration interaction theory, effectively unpaired electrons lay the foundation of the electron correlation measure in terms of total number of the electrons (molecular chemical susceptibility). graphs and their singularities with respect to the interatomic distance allow presenting a quantitative description of stretching and breaking of chemical bonds. The approach validity is demonstrated on a large number of bonds of different order and chemical composition.Comment: 24 pages, 17 figures, 4 tables, Advances in Quantum Chemistry, vol. 70, 201

Development and Validation of a Tokamak Skin Effect Transformer model

A control oriented, lumped parameter model for the tokamak transformer including the slow flux penetration in the plasma (skin effect transformer model) is presented. The model does not require detailed or explicit information about plasma profiles or geometry. Instead, this information is lumped in system variables, parameters and inputs. The model has an exact mathematical structure built from energy and flux conservation theorems, predicting the evolution and non linear interaction of the plasma current and internal inductance as functions of the primary coil currents, plasma resistance, non-inductive current drive and the loop voltage at a specific location inside the plasma (equilibrium loop voltage). Loop voltage profile in the plasma is substituted by a three-point discretization, and ordinary differential equations are used to predict the equilibrium loop voltage as function of the boundary and resistive loop voltages. This provides a model for equilibrium loop voltage evolution, which is reminiscent of the skin effect. The order and parameters of this differential equation are determined empirically using system identification techniques. Fast plasma current modulation experiments with Random Binary Signals (RBS) have been conducted in the TCV tokamak to generate the required data for the analysis. Plasma current was modulated in Ohmic conditions between 200kA and 300kA with 30ms rise time, several times faster than its time constant L/R\approx200ms. The model explains the most salient features of the plasma current transients without requiring detailed or explicit information about resistivity profiles. This proves that lumped parameter modeling approach can be used to predict the time evolution of bulk plasma properties such as plasma inductance or current with reasonable accuracy; at least in Ohmic conditions without external heating and current drive sources

Current ramps in tokamaks: from present experiments to ITER scenarios

In order to prepare adequate current ramp-up and ramp-down scenarios for ITER, present experiments from various tokamaks have been analysed by means of integrated modelling in view of determining relevant heat transport models for these operation phases. A set of empirical heat transport models for L-mode (namely, the Bohm-gyroBohm model and scaling based models with a specific fixed radial shape and energy confinement time factors of H(96-L) = 0.6 or H(IPB98) = 0.4) has been validated on a multi-machine experimental dataset for predicting the l(i) dynamics within +/- 0.15 accuracy during current ramp-up and ramp-down phases. Simulations using the Coppi-Tang or GLF23 models (applied up to the LCFS) overestimate or underestimate the internal inductance beyond this accuracy (more than +/- 0.2 discrepancy in some cases). The most accurate heat transport models are then applied to projections to ITER current ramp-up, focusing on the baseline inductive scenario (main heating plateau current of I(p) = 15 MA). These projections include a sensitivity study to various assumptions of the simulation. While the heat transport model is at the heart of such simulations (because of the intrinsic dependence of the plasma resistivity on electron temperature, among other parameters), more comprehensive simulations are required to test all operational aspects of the current ramp-up and ramp-down phases of ITER scenarios. Recent examples of such simulations, involving coupled core transport codes, free-boundary equilibrium solvers and a poloidal field (PF) systems controller are also described, focusing on ITER current ramp-down.</p

THE METHOD OF THE CAPPAMETER OF SOILS AND ITS APPLICATION TO THE SEARCH OF THE SULPHIDE ORES IN KARELIA

Developed and delivered to the industrial production the field cappameter IPK-2, the methods of the field works and the processing of the soil cappametry results have been justified, the efficiency of method in complex with the magnetic and litogeochemical photographies with the search of the sulphide ores in Karelia has been shown. The developed cappameter has been delivered to the Joint-Stock Company &quot;Uralchermetautomatics&quot;, where it is manufactured under the grade IPK-2; the methodical guides by the cappemetry of soils have been developedAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio