Global circuit response to the 11-year solar cycle: Changes in source or in medium?

© International Conference on Atmospheric Electricity, ICAE 2014 Modifications to both the DC and AC global circuits are considered on both short time scales and on the 11-year solar cycle time scale. New long-term records of Schumann resonances are considered as documentation of the AC global circuit. In most cases, changes in the medium of the global circuit provide a better qualitative explanation than intrinsic source changes (i.e., lightning and electrified clouds) for the variations in the global circuit. Further work is needed with the quantitative details

Effects of Energetic Solar Emissions on the Earth–Ionosphere Cavity of Schumann Resonances

© 2016, Springer Science+Business Media Dordrecht. Schumann resonances (SR) are the electromagnetic oscillations of the spherical cavity bounded by the electrically conductive Earth and the conductive but dissipative lower ionosphere (Schumann in Z Naturforsch A 7:6627–6628, 1952). Energetic emissions from the Sun can exert a varied influence on the various parameters of the Earth’s SR: modal frequencies, amplitudes and dissipation parameters. The SR response at multiple receiving stations is considered for two extraordinary solar events from Solar Cycle 23: the Bastille Day event (July 14, 2000) and the Halloween event (October/November 2003). Distinct differences are noted in the ionospheric depths of penetration for X-radiation and solar protons with correspondingly distinct signs of the frequency response. The preferential impact of the protons in the magnetically unshielded polar regions leads to a marked anisotropic frequency response in the two magnetic field components. The general immunity of SR amplitudes to these extreme external perturbations serves to remind us that the amplitude parameter is largely controlled by lightning activity within the Earth–ionosphere cavity

On certain approaches to the control methods development for the precipitation formation processes in convective clouds

The article aims at searching for the optimal way of emission of ice nucleating agent in convective cloud in order to prevent ‎formation of harmful hail by analyzing simulations of this process within a numerical model ‎of cloud‎. The state of the physics of clouds and active influences on them is discussed. It is noted that at the present time studies of the regularities of the formation and development of clouds as a whole begin taking into account their systemic properties. The main directions of research at the next stage of its development are discussed. The features of the existing methods of active action on convective clouds are noted, the main tasks encountered in the development of methods for controlling sedimentation in convective clouds by introducing reagents are formulated. It is noted that research on the development of methods for active influence on clouds should be conducted on the basis of new and more effective approaches, which should be based on the extensive use of mathematical modeling. Some approaches to solving this problem are discussed. According to the authors, the most promising of them are approaches based on the theory of optimal control and bifurcation theory. Some results of numerical modeling of the active effect on convective clouds are given

Ionospheric Non-linear Effects Observed During Very-Long-Distance HF Propagation

A new super-long-range wave propagation technique was implemented at different High Frequency (HF) heating facilities. The HF waves radiated by a powerful heater were scattered into the ionospheric waveguide by the stimulated field aligned striations. This waveguide was formed in a valley region between the E- and F- layers of the ionosphere. The wave trapping and channeling provide super-long-range propagation of HF heater signals detected at the Ukrainian Antarctic Academik Vernadsky Station (UAS) which is many thousand kilometers away from the corresponding HF heating facility. This paper aims to study the excitation of the ionospheric waveguide due to the scattering of the HF heating wave by artificial field aligned irregularities. In addition, the probing of stimulated ionospheric irregularities can be obtained from analyses of the signals received at far distance from the HF heater. The paper uses a novel method of scattering of the HF radiation by the heating facility for diagnostics of non-linear effects at the super-long radio paths. Experiments were conducted at three different powerful HF facilities: EISCAT (Norway), HAARP (Alaska), and Arecibo (Puerto Rico) and by using different far spaced receiving sites. The key problems for super-long-range propagation regime is the feeding of ionospheric waveguide. Then the energy needs to exit from the waveguide at a specific location to be detected by the surface-based receiver. During our studies the waveguide feeding was provided by the scattering of HF waves by the artificial ionospheric turbulence (AIT) above the HF heater. An interesting opportunity for the channeling of the HF signals occurs due to the aspect scattering of radio waves by field aligned irregularities (FAI), when the scattering vector is parallel to the Earth surface. Such FAIs geometry takes place over the Arecibo facility. Here FAI are oriented along the geomagnetic field line inclined by 43 degrees. Since the Arecibo HF beam is vertical, the aspect scattered waves will be oriented almost horizontally toward the South. Such geometry provides unique opportunity to channel the radio wave energy into the ionospheric waveguide and excites the whispering gallery modes

Solar Cycle-Modulated Deformation of the Earth–Ionosphere Cavity

The Earth–ionosphere cavity resonator is occupied primarily by the electromagnetic radiation of lightning below 100 Hz. The phenomenon is known as Schumann resonances (SR). SR intensity is an excellent indicator of lightning activity and its distribution on global scales. However, long-term measurements from high latitude SR stations revealed a pronounced in-phase solar cycle modulation of SR intensity seemingly contradicting optical observations of lightning from satellite, which do not show any significant solar cycle variation in the intensity and spatial distribution of lightning activity on the global scale. The solar cycle-modulated local deformation of the Earth–ionosphere cavity by the ionization of energetic electron precipitation (EEP) has been suggested as a possible phenomenon that may account for the observed long-term modulation of SR intensity. Precipitating electrons in the energy range of 1–300 keV can affect the Earth–ionosphere cavity resonator in the altitude range of about 70–110 km and modify the SR intensities. However, until now there was no direct evidence documented in the literature supporting this suggestion. In this paper we present long-term SR intensity records from eight stations, each equipped with a pair of induction coil magnetometers: five high latitude (|lat| \u3e 60°), two mid-high latitude (50° \u3c |lat| \u3c 60°) and one low latitude (|lat| \u3c 30°). These long-term, ground-based SR intensity records are compared on the annual and interannual timescales with the fluxes of precipitating 30–300 keV medium energy electrons provided by the POES NOAA-15 satellite and on the daily timescale with electron precipitation events identified using a SuperDARN radar in Antarctica. The long-term variation of the Earth–ionosphere waveguide’s effective height, as inferred from its cutoff frequency, is independently analyzed based on spectra recorded by the DEMETER satellite. It is shown that to account for all our observations one needs to consider both the effect of solar X-rays and EEP which modify the quality factor of the cavity and deform it dominantly over low- and high latitudes, respectively. Our results suggest that SR measurements should be considered as an alternative tool for collecting information about and thus monitoring changes in the ionization state of the lower ionosphere associated with EEP

Описання бета-розподілом масових годинних викидів твердих частинок дизеля з урахуванням паспортної точності газоаналізатора

Relevance of the study is that qualitative and quantitative results of solving of its tasks suitable for developing of methodic of decreasing of methodical errors of determination of values of mass hourly emission of particulate matter in exhaust gas flow of reciprocating internal combustion engine with using of conversion formula and readings of opacimeter and gas analyzer. Purpose of the study is obtaining of parameters of beta-distribution that approximate the empirical law of distribution of values of mass hourly emission of particulate matter in exhaust gas flow of reciprocating internal combustion engine which achieved by in direct measuring with taking into account the accuracy of direct measuring of its components that has nonlinear impact. Task of the study is obtaining of rational values of number of multiple measuring of coefficient of atenuation of light flux and volume concentration of unburned hydrocarbons in exhaust gas on individual operational regime of diesel engine during bench motor tests for case of automation of measuring process. Methodic of the study is in consistently application of following methods: analysis of scientific and technical literature, analysis of data of bench motor tests, application of prof. Parsadanov conversion formula, mathematical apparatus of beta-distribution, numerical calculation studies. It was detected that empirical distribution of values of mass hourly emission of particulate matter in exhaust gas flow of reciprocating internal combustion engine which obtained with using of one of known conversion formula of prof. Parsadanov as the function of indicator of opacity and toxicity of exhaust gas, has a significant difference from the normal distribution law at number of measurements less than 50 even in case of confirmation of the hypothesis of normality of distribution law of readings of opacimeter into limits of its passport measuring errors. That results were described by the mathematical apparatus of beta-distribution by carrying out the numerical calculation studies with using of program product written of the language Borland Pascal 7.0. The parameters of beta-distribution were obtain as the function of number of multiple measuring.Актуальність дослідження полягає в тому, що кількісні та якісні результати вирішення задач дослідження придатні для створення методики зниження методологічної похибки визначення величини масового годинного викиду твердих частинок з потоком відпрацьованих газів поршневого двигуна внутрішнього згоряння з використанням формул перерахунку та показів димоміра й газоаналізатора. Метою дослідження є отримання параметрів бета-щільності, що апрокси-мує емпіричний закон розподілу значень годинних масових викидів ТЧ з потоком ВГ поршневого ДВЗ, отриманих непрямими вимірюваннями з урахуванням точності прямих вимірювань їх складових, що чинять нелінійний вплив. Завданням дослідження є отримання раціональних значень кількості багаторазових вимірювань коефіцієнта послаблення світлового потоку та об’ємної концентрації незгорілих вуглеводнів у ВГ на одному режимі роботи дизеля у стендових моторних дослідженнях для випадку автоматизації процесу вимірювань. Методика виконання даної наукової роботи полягала у послідовному використанні наступних методів: аналіз науково-технічної літератури, методика аналізу даних мо-торних стендових випробувань, методика застосування формули перерахунку проф. І.В. Парсаданова, математичний апарат бета-розподілу, метод чисельних розрахункових досліджень. Встановлено, що емпіричний розподіл значень масового годинного викиду ТЧ з ВГ поршневого ДВЗ, отриманих при застосуванні однієї з відомих формул перерахунку проф. І.В. Парсаданова, як функція показників димності й токсичності ВГ, суттєво відрізняється від нормального закону за кількості вимірювань, меншій за 50, навіть при підтвердженні гіпотези про нормальність розподілу показів димоміра у межах паспортної похибки вимірювань. Результати описано математичним апаратом бета-розподілу шляхом здійснення розрахункового дослідження з використанням програмного продукту, розробленого у середовищі Borland Pascal 7.0. Отримано параметри бета-щільності для описання досліджуваного показника екологічної безпеки та їх залежності від кількості вимірювань

Evaluation of the Lattice Energy of the Two-Component Molecular Crystals Using Solid-State Density Functional Theory

The lattice energy <i>E</i>_latt of the two-component crystals (three co-crystals, a salt, and a hydrate) is evaluated using two schemes. The first one is based on the total energy of the crystal and its components computed using the solid-state density functional theory method with the plane-wave basis set. The second approach explores intermolecular energies estimated using the bond critical point parameters obtained from the Bader analysis of crystalline electron density or the pairwise potentials. The <i>E</i>_latt values of two-component crystals are found to be lower or equal to the sum of the absolute sublimation enthalpies of the pure components. The computed energies of the supramolecular synthons vary from ∼80 to ∼30 kJ/mol and decrease in the following order: acid–amide > acid–pyridine > hydroxyl–acid > amide–amide > hydroxyl–pyridine. The contributions from different types of noncovalent interactions to the <i>E</i>_latt value are analyzed. We found that at least 50% of the lattice energy comes from the heterosynthon and a few relatively strong H-bonds between the heterodimer and the adjacent molecules

FIRE RESISTANCE OF REINFORCED CONCRETE AND STEEL STRUCTURES

The scientific bases of ensuring fire resistance of reinforced concrete and steel building structures in the conditions of modern extreme influences are laid. The current state of fire safety of buildings and structures, as well as approaches, methods and tools for its assessment are analyzed. Analysis of emergencies and fires in the world has shown that the vast majority of them occur in buildings and structures. It is shown that the cause of catastrophic consequences and destruction is the non-compliance of the actual limit of fire resistance of building structures with regulatory requirements. This is due to the imperfection of methods and means of assessing the fire resistance of building structures, including fire-retardant. To overcome the shortcomings identified during the analysis, the paper develops physical and mathematical models of thermal processes occurring in the fire-retardant reinforced concrete structure. Based on the proposed models, a computational-experimental method for estimating the fire resistance of such structures has been developed. The efficiency of the proposed method was tested by identifying the relationship between the parameters of the fire-retardant plaster coating “Neospray” and the fire resistance of fire-retardant multi-hollow reinforced concrete floor. The study of fire resistance of steel structures is proposed to be carried out using reduced samples in the form of steel plates with dimensions of 500×500×5 mm. Based on the proposed models, a calculation and experimental method for estimating the fire resistance of steel structures, as well as an algorithm and procedures for its implementation have been developed. The verification of the efficiency of the proposed method was carried out in the ANSYS software package using the aged coating “Phoenix STS” and the coating “Amotherm Steel Wb” under heating conditions at the temperature of the hydrocarbon fire. The reliability of the developed models and methods is checked. It is established that random errors in temperature measurement significantly affect the accuracy of determining the thermophysical characteristics and limits of fire resistance. In general, the efficiency of the proposed calculation and experimental methods with sufficient accuracy for engineering calculations is confirmed