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Assessing the role of anthropogenic warming from temporally inhomogeneous historical data in the presence of large natural variability is difficult and has caused conflicting conclusions on detection and attribution of tropical cyclone (TC) trends. Here, using a reconstructed long-term proxy of annual TC numbers together with high-resolution climate model experiments, we show robust declining trends in the annual number of TCs at global and regional scales during the twentieth century. The Twentieth Century Reanalysis (20CR) dataset is used for reconstruction because, compared with other reanalyses, it assimilates only sea-level pressure fields rather than utilize all available observations in the troposphere, making it less sensitive to temporal inhomogeneities in the observations. It can also capture TC signatures from the pre-satellite era reasonably well. The declining trends found are consistent with the twentieth century weakening of the Hadley and Walker circulations, which make conditions for TC formation less favourable.

A method of manufacturing double-lattice magnetoplasmonic crystals with the structure (Au/BIG)2, in which the plasmon gold lattices are displaced relative to each other by half a period, has been presented. Gold films with thicknesses of about 40 nm have been formed by the ion-beam sputtering–deposition method, while the adhesive properties of the films allow the dimensional etching by a sharp-focused ion beam. It has been shown that the formation of the second plasmon lattice located on top of the 100 nm thick garnet layer allows the preserving of the periodicity of the first Au lattice. However, there is a significant influence of diffusion spreading on the lower lattice material, which leads to a decrease in its density. The dependence of the intensity magnetooptical effect in the geometry on the transmission as a function of the thickness of the upper lattice and presence of an additional layer of Ta2O5has been studied.

The El Niño/Southern Oscillation (ENSO) drives substantial variability in tropical cyclone (TC) activity around the world. However, it remains uncertain how the projected future changes in ENSO under greenhouse warming will affect TC activity, apart from an expectation that the overall frequency of TCs is likely to decrease for most ocean basins. Here we show robust changes in ENSO-driven variability in TC occurrence by the late twenty-first century. In particular, we show that TCs become more frequent (∼20–40%) during future-climate El Niño events compared with present-climate El Niño events—and less frequent during future-climate La Niña events—around a group of small island nations (for example, Fiji, Vanuatu, Marshall Islands and Hawaii) in the Pacific. We examine TCs across 20 models from the Coupled Model Intercomparison Project phase 5 database, forced under historical and greenhouse warming conditions. The 12 most realistic models identified show a strong consensus on El Niño-driven changes in future-climate large-scale environmental conditions that modulate development of TCs over the off-equatorial western Pacific and the central North Pacific regions. These results have important implications for climate change and adaptation pathways for the vulnerable Pacific island nations.

An engineering technique has been developed to optimize the long-wavelength cutoff of the operating spectral band of mirror optoelectronic devices designed to detect point objects against the background of outer space. The proposed technique makes it possible to choose the optimal operating spectral band to minimize the mass and dimensions of the desired optical system. The negative influence caused by increasing the number of mirror optical components on the operating range of the optoelectronic device is shown.

Abstract This paper presents a review of the most interesting observations of low-frequency plasma waves together with plasma particles which were made by the Interball 1, Magion 4 and Prognoz 8 satellites in the outer polar cusp. Accelerated plasma particles, hot electron populations and very strong wave activity, particularly at low frequencies, are observed. A detailed study of the wave spectra together with the distribution function for electrons indicate the correlation between the presence of lower-hybrid waves and the population of the particles with higher energy than in the surrounding space. These experimental facts suggest that strong coupling between waves and particles is responsible for plasma heating. During polar cusp crossings by Interball 1 and Prognoz 8, FFT analysis of the wave form indicates many bursts of ULF emissions in both electric and magnetic components. These waves have highly non-stationary characteristics. To study the dynamics of changes in the spectral characteristics of the waves wavelet analysis has been used. Nonlinear interactions are studied using bispectral methods of analysis. This presentation gives the results of such an analysis for selected cusp crossings at different altitudes. An example of wave activity registered by the STAFF instrument onboard the CLUSTER spacecraft in the polar cusp is also presented.

Abstract We present both statistical and case studies of magnetosheath interaction with the high-latitude magnetopause on the basis of Interball-1 and other ISTP spacecraft data. We discuss those data along with recently published results on the topology of cusp-magnetosheath transition and the roles of nonlinear disturbances in mass and energy transfer across the high-latitude magnetopause. For sunward dipole tilts, a cusp throat is magnetically open for direct interaction with the incident flow that results in the creation of a turbulent boundary layer (TBL) over an indented magnetopause and downstream of the cusp. For antisunward tilts, the cusp throat is closed by a smooth magnetopause; demagnetized ‘plasma balls’ (with scale ∼ few RE, an occurrence rate of ∼25% and trapped energetic particles) present a major magnetosheath plasma channel just inside the cusp. The flow interacts with the ‘plasma balls’ via reflected waves, which trigger a chaotization of up to 40% of the upstream kinetic energy. These waves propagate upstream of the TBL and initiate amplification of the existing magnetosheath waves and their cascade-like decays during downstream passage throughout the TBL. The most striking feature of the nonlinear interaction is the appearance of magnetosonic jets, accelerated up to an Alfvenic Mach number of 3. The characteristic impulsive local momentum loss is followed by decelerated Alfvenic flows and modulated by the TBL waves; momentum balance is conserved only on time scales of the Alfvenic flows (1/fA ∼12 min). Wave trains at fA∼1.3 mHz are capable of synchronizing interactions throughout the outer and inner boundary layers. The sonic/Alfvenic flows, bounded by current sheets, control the TBL spectral shape and result in non-Gaussian statistical characteristics of the disturbances, indicating the fluctuation intermittency. We suggest that the multi-scale TBL processes play at least a comparable role to that of macro-reconnection (remote from or in the cusp) in solar wind energy transformation and population of the magnetosphere by the magnetosheath plasma. Secondary micro-reconnection constitutes a necessary chain at the small-scale (∼ion gyroradius) edge of the TBL cascades. The thick TBL transforms the flow energy, including deceleration and heating of the flow in the open throat, ‘plasma ball’ and the region downstream of the cusp.

The strength characteristics of composites based on four types of modified epoxy resins and reinforced with carbon fabric were studied as influenced by the filler content. The experimental and theoretical strength parameters of the composites were compared. The correlation between the adhesion strength at the polymeric binder-filler boundary and the impact resilience of the composites was evaluated; a procedure was proposed for predicting the impact resilience of the reinforced composites.

The kinetics of low-temperature formation of interpenetrating polymer networks based on modified epoxy resins and copolymers of unsaturated oligoester resin with oligoether acrylates were studied in relation to the composition of the initial mixture. The influence of the parameters of the three-dimensional structure (cross-linking density, content of lattice points, number of monomeric units in cross-links) on the strength characteristics of the resulting polymer networks was examined, and the best conditions were found for preparing shockproof materials.

The reliability of predictive control of product parameters in the presence of additive and multiplicative measurement errors is evaluated.

At close to 2345 UT on September 24, 1998, the magnetosphere was suddenly compressed by the passage of an interplanetary shock. In order to properly interpret the magnetospheric events triggered by the arrival of this shock, we calculate the orientation of the shock, its velocity, and its estimated time of arrival at the nose of the magnetosphere. Our best fit shock normal has an orientation of (−0.981 −0.157 −0.112) in solar ecliptic coordinates, a speed of 769 km/s, and an arrival time of 2344:19 at the magnetopause at 10 RE. Since measurements of the solar wind and interplanetary magnetic field are available from multiple spacecraft, we can compare several different techniques of shock‐normal determination. Of the single spacecraft techniques the magnetic coplanarity solution is most accurate and the mixed mode solution is of lesser accuracy. Uncertainty in the timing and location of the IMP 8 spacecraft limits the accuracy of solutions using the time of arrival at the position of IMP 8.

We consider the problem of determining the reliability of control when measurement error depends on component parameters. The error model we use is a polynomial.

Abstract: Three experiments on the tellurium recrystallization by a modified Bridgman method were performed under microgravity conditions on board the Mir orbital space laboratory using a ChSK-1 Kristallizator furnace. The physical properties of samples were studied, including the final crystal structure, the distribution of impurities and defects, and the charge carrier concentration and mobility. The results were compared to the analogous parameters of crystals remelted using the same method under the normal gravity conditions. It is established that the samples recrystallized in a close volume under the on-board microgravity conditions “break off” from the container walls and touch the walls only in a few points. This circumstance gives rise to special effects, such as the growth of crystals with a free surface and deep supercooling. Study of the distribution of electrically active impurities over the length of ingots shows evidence of the presence of thermocapillary convective flows in the melt under the microgravity conditions. The flows tend to increase upon separation of the melt from the container walls. The contributions due to impurities and electrically active structural defects to the charge carrier distribution are taken into account. The single-crystal sample obtained upon the partial recrystallization of tellurium in a close container volume under the on-board microgravity conditions exhibits the electrical characteristics comparable to those of a crystal grown by the Czochralski technique under the normal gravity conditions.

The plasma-wave experiment ASPI (analysis of spectra of plasma waves and instabilities) on board the INTERBALL spacecraft is a combined wave diagnostics experiment. It performs measurements of the DC and AC magnetic field vector by flux-gate and searchcoil sensors, the DC and AC electric field vector by Langmuir double probes and the plasma current by Langmuir split probe. Preliminary data analysis shows the low noise levels of the sensors and the compatibility of new data with the results of previous missions. During several months of in-orbit operation a rich collection of data was acquired, examples of which at the magnetopause and plasma sheet are presented in second part of the paper.

A short description of the SAS (subsatellite analyser of spectra) wave experiment on board the Magion-4 subsatellite is given. We present first measurements of the magnetic-field fluctuations in the frequency range 32–2000 Hz obtained in the magnetotail during the disturbed period at the magnetopause and in the polar cusp.

The polar cusp being a region of the free access of the solar wind into the inner magnetosphere is also the site of turbulent plasma flow. Satellites Interball Tail probe and Prognoz-8 with their orbits with apogee about 30REand an inclination of 65° crossed the polar cusps many times. Magion-4 being the subsatellite for Interball-1 (Tail Probe) had the same orbit as the main satellite. In this presentation we discuss results of measurements the spectra of magnetic field fluctuations in the frequency range 30–2000Hz registered onboard Magion-4. During many crossings of the outer polar cusp the broad band emissions, lower hybrid and electron cyclotron harmonics were registered. The correlation of these emissions with plasma spectra is also presented.

The effect of small inclinations and low-amplitude rocking on thermal convection in an air-filled cube with sides 3 cm long has been investigated experimentally and numerically for steady and periodic heating from above. Expressions have been obtained for the dependence of the temperature difference between two points inside the cube on the angle of inclination, the applied vertical temperature difference, the rocking frequencies and the oscillations of the heating power. The possibility of estimating the magnitude and direction of the microacceleration vector on the basis of temperature field measurements made under orbital flight conditions is discussed.

Component parameter monitoring reliability is estimated when the errors of measurement are dependent on the parameters. The solution amounts to a standard classical evaluation of monitoring reliability with statistical independence between the errors of measurement and the parameters.

We present Prognoz-8 observations of low-frequency plasma waves (2-105 Hz) associated with plasma fluxes near the outer boundary of the plasma sheet. These plasma fluxes were different from the regular plasma sheet boundary layer and consisted of tailward flowing warm proton and cold oxygen beams accompanied by rather cold electrons (Te less than 100 eV). Observed plasma characteristics were used in the numerical solution of the dispersion relation for the ion-beam acoustic instability. Detailed analysis shows that this instability can be a source of observed emissions at frequencies up to 25 Hz.

1.The influence of a large group of metal cations on the course of the reaction of a second azo-combination of monoazo-derivatives of chromotropic acid was studied. The best catalysts are salts of the alkali and alkaline-earth elements.2.The indices of reactivity of model forms of compounds in the approximations of isolated and reacting molecules were calculated by the Hückel MO LCAO method. An interpretation of the reactivity in the latter approximation was given.3.Molecular diagrams are cited for the azo-components, their complexes with Ca and Be, and the polarized products.

We report the experimental characterization of mechanically induced long-period fiber gratings (LPFG’s) made by pressing a plate with periodic grooves against a short length of fiber. This filter, which is simple and inexpensive, exhibits transmission spectra and temperature stability similar to those of photoinduced LPFG’s. It also offers the unique advantages of being tunable, erasable, and reconfigurable. Its polarization dependence also makes it useful as a polarizer, although it can also be eliminated with simple mechanical designs.

Abstract: A description is given of a method of improving the accuracy of measurement of the frequency of electrical signals on the basis of their transformation. The method makes it possible to eliminate the additive component of the measurement error and reduce the multiplicative component.

It is shown that construction of the calibration characteristics of measuring devices may be reduced to expansion of these characteristics into Chebyshev polynomials. The coefficients of these polynomials (i.e., the parameters of the calibration characteristics) are determined by means of spectrum analyzers as the coefficients of the expansion into a Fourier series of the output signal of the device that arise when cosine signals arrive at the device 's input.

A method for calculating the time of the dynamic additional impact to the elements of a reinforced concrete framing structural system under special impact caused by a sudden loss of stability of a compressed bearing element is presented. Using the discrete-linear moment-curvature diagram for reinforced concrete compressed-bended element, the analytical relationships for different stages of deformation of a reinforced concrete element before and after cracking are carried out. The obtained relationships for time of the additional dynamic impact to the elements makes it possible to determine the dynamic strength of concrete and reinforcement and the stiffness of the sections of reinforced concrete elements of structural systems under such impacts more accurately and consequently ensure more exact computational analysis to progressive collapse.

Tropical cyclones (TCs) can have severe impacts on Australia. These include extreme rainfall and winds, and coastal hazards such as destructive waves, storm surges, estuarine flooding, and coastal erosion. Various aspects of TCs in the Australian region have been documented over the past several decades. In recent years, increasing emphasis has been placed on human‐induced climate change effects on TCs in the Australian region and elsewhere around the globe. However, large natural variability and the lack of consistent long‐term TC observations have often complicated the detection and attribution of TC trends. Efforts have been made to improve TC records for Australia over the past decades, but it is still unclear whether such records are sufficient to provide better understanding of the impacts of natural climate variability and climate change. It is important to note that the damage costs associated with tropical cyclones in Australia have increased in recent decades and will continue to increase due to growing coastal settlement and infrastructure development. Therefore, it is critical that any coastal infrastructure planning and engineering decisions, as well as disaster management decisions, strongly consider future risks from tropical cyclones. A better understanding of tropical cyclones in a changing climate will provide key insights that can help mitigate impacts of tropical cyclones on vulnerable communities. An objective assessment of the Australian TCs at regional scale and its link with climate variability and change using improved and up‐to‐date data records is more imperative now than before. This article is categorized under:Paleoclimates and Current Trends > Modern Climate Change Tropical cyclone frequency in the Australian region and the potential influences of monitoring methods and technologies on the best track database since 1900.

Authors modelled frame-bracing structural system resistance against progressive collapse at sudden buckling one of the compressed bearing elements of system in the paper. In the foundation of problem algorithmization it is put principle of initial structure dividing to substructures, combination of numerical and analytical methods at multistage calculation. Determination of critical force in compressed reinforced concrete elements of chosen substructure is carried out combining the initial parameters method and the displacement method. On the energy basis using works values at initial and end section it is evaluated nearby elements influence level on buckling of the most compressed rod. The numerical results of developed algorithm realization for substructure of reinforced concrete frame-bracing structural system of multi-storey building made of panel-frame elements are presented in the paper.

The paper deals with the deformation of reinforced concrete structural systems of multi-story buildings and structures under accidental impacts. One of these impacts is instantaneous removal of a bearing element of a system. Before this moment researches of survivability and resistance against progressive collapse of structural systems under such impacts were based on the strength criteria. At the same time instantaneous removal of structural element may be caused by loss of stability at evolutionary accumulation of corrosion damages or other physical impacts. That is why the deformation criteria of loss of stability of a structural system under accidental impacts are proposed in this paper. The energy approach and the mixed method of structural mechanics are applied to evaluate survivability and resistance against progressive collapse of a structural system at loss of stability of a bearing element. Two - level computational models are used to solve this problem. An example of calculation of 14-storey building under such impact in accordance to deformation criteria is presented. It is shown, that critical force, that lead the structural system to progressive collapse at evolutionary accumulation of damages is less then ultimate compressive force, which were calculated in accordance to strength criteria.

A method is considered for making high-precision frequency measurements with simple, inexpensive, and inexact frequency meters.