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• Pulsed laser welding of E110 alloy is a challenge. • Modified layer was relaxed in conditions like in a nuclear reactor for 200 h. • Modified layer did not protect from corrosion and high-temperature oxidation. • Structure of base metal and welds after high-temperature oxidation are quite similar. Corrosion and high-temperature steam oxidation of E110 alloy and its pulsed laser welds were investigated. An attempt to improve performance properties has been made by modifying the surface with a pulsed ion beam. The properties of welded joints that affect their resistance to corrosion and high-temperature steam oxidation are presented. The results of the study of surfaces and cross-sections of the pre- and non-irradiated samples after autoclave corrosion test of high-temperature steam oxidation are shown and discussed. It was concluded that there are no reasons to recommend the studied technology of surface modification to the nuclear industry. [ABSTRACT FROM AUTHOR]

The advantages of a quantitative estimation of hydrophysical properties of the soil during pre-design research in hydraulic engineering in the urban environment are considered based on the example of cofferdam project planning. The method allows to eliminate time-consuming laboratory tests and promptly to obtain reliable estimates of water-retention capacity and hydraulic conductivity of the soil using the available data of the physical soil properties. The method based on a mathematical model for hydrophysical soil properties assuming as a capillary-porous media. Such method and associated technologies can be used in a way of underground development. [ABSTRACT FROM AUTHOR]

This work is based on analysis of flood events using GIS-environment and managerial solutions to prevent them. General concepts and statistical data are given. Modern GIS-technologies, which are used for flash flood hydrological model creation, are examined. The test models, which allow analyzing possible engineering solution with the aim of minimization of risks and consequences, are developed. All the proposed measures requires preliminary soil properties researches and underground surveys. [ABSTRACT FROM AUTHOR]

This paper deals with the problems associated with the design and operation of once–through or combined water cooling systems of nuclear power plants using sea water. Suggested refinement techniques of physical modeling of hydraulic processes at the pre–stage using multipurpose hydraulic stand. An example of such a construction of the stand and the experience of its use in the justification of the design decisions of waterworks of energy facilities. [ABSTRACT FROM AUTHOR]

In the article, the question of suburban areas’ development, where construction was carried out under complicated hydrological and geological conditions, was discussed. The development of the area with a small watercourse, which bogs the site and makes the construction more difficult, is considered. Hydrological, geological and meteorological components of the area's condition were analyzed and the recommendations concerning protection the area from a flooding were given. [ABSTRACT FROM AUTHOR]

Currently in St. Petersburg problem of reconstruction of hydraulic structures on the small streams of the city is a particularly urgent problem. However, despite the fact that in recent years during such operations side by side with traditional technologies new methods are used, practically there is a lack of publications about organization and planning of hydraulic construction works. The authors of this publication enough acquainted with the history and current state of the work of this kind, which was the basis for this publication. The paper is based on a review of the key technologies used in the reconstruction of the hydraulic facilities in St. Petersburg. [ABSTRACT FROM AUTHOR]

The paper is devoted to the problem of fault detection in technical systems described by nonlinear dynamical models containing non-smooth nonlinearities. So-called “model-free” or “data-driven” method is used to solve the problem. The feature of this method is that parameters of the system under consideration may be unknown. The algebra of functions is used to solve the problem under consideration. [ABSTRACT FROM AUTHOR]

The kinetics of an outer-sphere nonadiabatic electron transfer reaction at the defective graphene is theoretically investigated. Different intrinsic and extrinsic point defects were analyzed. The band structure from DFT, in combination with the Gerischer model, was used for the predictions. Calculations were done taking into account the quantum capacitance of the surface for the correct prediction of alignment and occupation of graphene electronic states upon contact with an electrolyte. We have shown that an electrochemical property of graphene largely depends on defect type due to differences in the electronic structure induced by defects. Due to small graphene quantum capacitance, the electron transfer kinetics can be modulated by changes in the double-layer capacitance. The deviations of the potential dependence of the rate constant from the Butler-Volmer kinetics are predicted. Image 1 [ABSTRACT FROM AUTHOR]

Event-related desynchronization (ERD) and synchronization (ERS) in the individually defined theta, alpha-1, alpha-2 and alpha-3 frequency bands were measured in 20 healthy subjects in response to International Affective Picture System (IAPS) stimuli with low, moderate and high arousal (LA, MA and HA) content. The 62-channel EEG, skin conductance response (SCR) and heart rate (HR) were simultaneously recorded while subjects viewed sequentially presented pictures and subjectively rated them after each presentation. In the theta band, both MA and HA vs. LA stimuli induced larger synchronization over the left anterior and bilaterally over posterior cortical leads. However, rather unexpectedly, both MA and HA vs. LA stimuli yielded larger alpha-1 synchronization, predominantly over occipital leads. In both theta and alpha-1 bands, affectively salient stimuli prompted larger ERS against the background of the overall dominance in power synchronization of posterior regions of the right hemisphere, irrespective of stimulus category. Finally, in the alpha-3 band, HA stimuli induce a lateralized time-dependent power increase over anterior leads of the left hemisphere. The hemispheric asymmetries revealed point to recruitment of not only posterior regions of the right hemisphere (theta and alpha-1 bands), but also of anterior regions of the left hemisphere (theta and alpha-3 bands) in affect analysis beyond valence dimension. In terms of affective chronometry, the significant arousal×time interactions clearly indicate that in the theta frequency band discrimination of affective stimuli has already started at 200 ms post-stimulus, whereas in the alpha-1 and alpha-3 bands this process is delayed by up to 800–1200 ms. [Copyright &y& Elsevier]

The study of optical and plasmonic properties of structures is an important step in the development of substrates for surface-enhanced Raman scattering (SERS) applications. In this work, structures based on a disordered array of hemispherical silver nanoparticles (AgNPs) on a single-crystal silicon (c-Si) substrate are studied. A simple and reproducible method is proposed in which an Ag island film obtained by chemical reduction of AgNO 3 is transformed after annealing at 350 °C into an array of hemispherical AgNPs on a thin SiO 2 layer. The average radii of AgNPs range from 30 to 130 nm, which can be varied due to the concentration of AgNO 3 in the initial deposition solution. Numerical calculations of the scattering, absorption, and extinction cross-sections are used to determine the positions of the localized surface plasmon resonance (LSPR) multipoles depending on the hemispherical AgNP size. The splitting of the LSPR dipole is found in the reflection spectra at oblique angles of incidence for p-polarization of light, which indicates the prolate shape of the hemispherical AgNPs. Finally, SERS shows reliable detection of 10−7 M (crystal violet) with the enhanced factor ∼ 6.2 × 10 5 and the relative standard deviation of signal ∼ 10 %. These studies suggest that hemispherical AgNPs on a SiO 2 @c-Si are promising candidates for detecting triphenylmethane dyes. [Display omitted] • SERS substrates based on hemispherical AgNPs on SiO 2 @c-Si have been fabricated. • FDTD calculations were used to determine LSPR multipoles as a function of AgNP size. • Splitting of the LSPR in the reflection spectra of p-polarized light was found. • Prolate shape of the AgNPs were confirmed by SEM method and optical investigations. • SERS substrates showed reliable CV detection of 10−7 M with EF ∼ 6.2 × 10 5 and RSD ∼ 10 %. [ABSTRACT FROM AUTHOR]

Zr 63.5 Cu 23 Al 9 Fe 4.5 amorphous and crystalline alloys were irradiated by high intensity pulsed ion beam to investigate the effects of transient high thermal load irradiation on their microstructure, surface reflectivity and nano-hardness. When the high temperature caused by transient thermal shock did not reach the melting temperature of the alloys, there was no obvious change in the phase-structure of amorphous and crystalline alloys, and irradiation had little impact on surface reflectivity and nano-hardness. When the temperature exceeding the melting temperature, amorphous alloys still maintained amorphous strtucture, and more free volumes generated by remelting and rapid solidification process, resulting in the reduction of nano-hardness; while micrometer-sized amorphization appeared in the crystalline counterpart, which also reduced the nano-hardness. Compared with molybdenum, a candidate material of the first mirror, there was no crack on the surface and less change of surface reflectivity in amorphous and crystalline alloys. [Display omitted] • HIPIB irradiated amorphous alloy had more free volume analyzed by nano-mechanics. • Amorphous transformation appeared in Zr-based crystal after HIPIB irradiation. • Less surface damage and reflectivity changes occurred in two alloys than molybdenum. • Hardness reduced but plasticity increased for two alloys after HIPIB irradiation. [ABSTRACT FROM AUTHOR]

Surface topography and elemental composition of craters formed on the surface of AISI 321 stainless steel after processing with powerful pulsed flows of Cn+ and H+ ions (accelerating voltage: 250 keV, pulse duration: approximately 100 ns) are studied. Processing is performed using single-pulse fluences of 1 and 3 J/cm2, with the number of pulses ranging from 1 to 50. It is determined that the average size of the craters increases and the number of craters decreases with an increase in the number of impact pulses. The average size and number of craters are not dependent on the degree of preliminary deformation of the samples. Based on the applied processing parameters, it is established that titanium sulfide or titanium carbosulfide inclusions are the preferred crater sites. Furthermore, the crater structure is examined through electron backscatter diffraction analysis. The structure and phase composition of the craters formed on steel as a result of exposure to a pulsed ion beam do not differ from the structural-phase state of the crater-free regions. • Craters are formed on the surface of AISI 321 steel after high-power ion-beam processing. • The craters are mainly formed on the nonmetallic inclusions. • With the increase in the number of impulses, the average size of the craters increases and their number decreases. • The structure and phase composition of the crater do not differ from the structural-phase state of the surfaces without craters. [ABSTRACT FROM AUTHOR]

Nine simple minerals and oxides, traditionally used as laboratory reference samples in the electron probe microanalysis (EPMA) of silicate minerals, have been quantitatively evaluated. Three separate series of data, comprising the average concentration, standard deviation, relative standard deviation, confidence interval and the z-score of data quality, were calculated for 21 control samples derived from calibrations obtained from three sets of reference samples: (1) simple minerals; (2) oxides; and (3) certified glass reference materials. No systematic difference was observed between the concentrations obtained from these three calibration sets when analyzed results were compared to certified compositions. The relative standard deviations obtained for each element were smaller than target values for all determinations. The z-score values for all elements determined fell within acceptable limits (−2

• Simulation of space weathering effects by micrometeorite impacts induced by pulsed intense infrared laser. • Differences in the microstructure of minerals due to the weathering source in space. • Transparency feature increases due to impact gardening. We studied space-weathering effects caused by micrometeorite bombardment simulated by pulsed intense infrared laser, generating ∼15 mJ per pulse in high vacuum. For our investigation, we selected a natural olivine (San Carlos olivine (Fo 91)) and a natural pyroxene (Bamble orthopyroxene (En 87)) as important rock forming minerals of the Earth upper mantle as well as key planetary minerals. Irradiated areas of powdered pressed samples were examined by optical reflection spectroscopy in a broad optical and infrared wavelength range (visible-, near-, and mid-infrared) and transmission electron microscopy to identify changes due to micrometeorite impacts. The present study aims to investigate especially the effects of micrometeorite bombardment on reflectance spectra in the mid-IR in preparation for future space missions, as well as for the MERTIS experiment onboard the BepiColombo mission. For both irradiated samples, we found a reduction in albedo and in the reflectance of characteristic Reststrahlen bands and an increase of the transparency feature. VIS and NIR spectra of both minerals show the typical darkening and reddening as described for other space-weathered samples. TEM studies revealed that space-weathered layers in olivine and pyroxene differ in their respective thickness, ∼450 nm in olivine, 100-250 nm in pyroxene, as well as in developed "nanostratigraphy" of laser-ablated material, like nanophase iron (npFe). In conclusion, our spectral and structural findings were compared to samples in which space weathering was caused by different processes. A comparison with these data demonstrates that there is no difference in optical reflectance spectroscopy, but a significant difference in the microstructure of minerals due to the weathering source in space, as there are solar wind and solar flares cause other structural and chemical changes as the bombardment with micrometeorites. [ABSTRACT FROM AUTHOR]