The problem of fault diagnosis in technical systems described by linear dynamic models is considered. The approach allowing increase robustness of the diagnostic process under disturbances is ...suggested. The approach includes two stages: (1) synthesis of sliding mode observer, sensitive to the disturbance and invariant with respect to the fault; this observer estimates the value of the disturbance, (2) synthesis of diagnostic observer, sensitive to the fault, using the estimated value of the disturbance giving by the first observer to compensate the effect of the disturbance; this observer provides fault detection. To isolate faults, the complex diagnostic tools are constructed.
Achieving efficient localization of white light at the nanoscale is a major challenge due to the diffraction limit, and nanoscale emitters generating light with a broadband spectrum require ...complicated engineering. Here we suggest a simple, yet highly efficient, nanoscale white-light source based on a hybrid Si/Au nanoparticle with ultrabroadband (1.3–3.4 eV) spectral characteristics. We incorporate this novel source into a scanning-probe microscope and observe broadband spectrum of photoluminescence that allows fast mapping of local optical response of advanced nanophotonic structures with submicron resolution, thus realizing ultrabroadband near-field nanospectroscopy.
We suggest a novel class of active nanoantennas based on diamond nanoparticles with embedded nitrogen-vacancy centres coupled to Mie resonances of nanoparticles. We theoretically study the optical ...properties of such nanoantennas including the field enhancement and Purcell effect, and experimentally demonstrate the enhancement of the fluorescence rate of the emitters due to particle resonances, as compared to a nonresonant regime. Our results pave the way towards active dielectric nanophotonics for quantum light sources, bioimaging, and quantum information processing.
Accumulation of essential/beneficial and non-essential chemical elements by submerged (Stuckenia pectinata (L.) Börner) and emergent (Phragmites australis (Cav.) Trin. ex Steud.) rooted macrophytes ...in three water bodies was studied as dependent on water salinity (specific conductivity) and main environmental factors (temperature, pH of water, growing period, element contents in water and sediments). Inductively coupled plasma optical emission spectrometry (ICP - OES) was used for the element detection in the plants, sediments, and water. Multivariate statistics redundancy analysis (RDA) showed that investigated factors together explained 37.8 - 44.7% and 29.9 - 42.6% of the essential/beneficial and non-essential elements variability, respectively, whereas salinity was one of the main factors determining the accumulation of a number of elements (Mg, S, Na, Li, Sr, Sb) by the macrophytes. A decrease in the essential element contents (K, P, N, Cu, Zn) was observed in both species of the macrophytes during the growing season. Environmental factors (salinity, growing period, and pH) were more significant than the element contents in water and the sediments for the essential/beneficial element accumulation by two species of the macrophytes. The element contents in the sediments to a greater extent determined non-essential element accumulation by P. australis than by S. pectinata. The study showed that the efficiency of using P. australis and S. pectinata for remediation of aquatic ecosystems contaminated by heavy metals should not decrease with a salinity increase.
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•Salinity increased Mg, S, Na, Li accumulation by submerged and emergent plants.•A decrease in K, P, N, Cu, Zn in the macrophytes was observed during growing season.•Environmental factors are significant for essential/beneficial macrophyte elements.
Polyethylene film is one of the most common types of recalcitrant plastic waste materials. Information regarding the fate of plastic films in soil is scarce compared to the fate of plastic films in ...aquatic environments. The aim of this study was to evaluate the effects of soil fauna and of impregnation of polyethylene films with oil on the colonization of low-density polyethylene films by prokaryotic communities. The field experiment was performed in a monsoon tropical forest (Vietnam). Polyethylene films were incubated in thermally pre-defaunated soil isolated from the surrounding soil by a stainless steel mesh. Three mesh sizes were used, allowing access to different size groups of soil fauna. The diversity, taxonomic structure and co-occurrence patterns in prokaryotic communities were studied using high-throughput sequencing of 16S rRNA gene libraries. The prokaryotic communities that formed on polyethylene films were slightly different from those inhabiting the surrounding soil. Contrary to our expectations, no difference in the diversity of prokaryotes was observed between microcosms with different mesh sizes. Oil impregnation also had only a minor influence on the prokaryotic community structure. Polyethylene films incubated in microcosms with soil appeared to be colonized by various consortia of prokaryotes as a barren and inert surface.
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•The effects of soil fauna and oil impregnation on the prokaryotic colonization of polyethylene films were studied.•The field experiment was performed in a monsoon tropical forest (southern Vietnam).•Soil fauna activity did not affect the structure or diversity of prokaryotic communities on polyethylene films.•Polyethylene films appear to be colonized by various consortia of prokaryotes as a barren and inert surface.
An increase in the duration of the period of high stability of the Antarctic polar vortex in late spring and early summer (November–December), which has been observed over the past 30 years, is ...observed. This trend is manifested both in the dynamics of the main characteristics of the polar vortex (vortex area and wind speed along the vortex boundary) and in the area of the Antarctic ozone hole. The dynamics of the polar vortex of 2020 is clear evidence of this phenomenon. During that time, unusually high wind speeds along the vortex boundary were recorded throughout the entire period of its existence; anomalous areas of the vortex and the ozone hole were observed from mid-November to December. In addition, the polar vortex existed until the last week of December, which is unprecedented. To analyze the dynamics of the Antarctic polar vortex, we used the method of vortex delineation on the basis of geopotential values, which were determined from the maximum temperature gradient and the maximum wind speed characterizing the boundaries of the vortex.
The relationship between a variety's genotype, environmental conditions and phytopathogenic load are the key factors contributing to high yields that should be taken into account in selecting donors ...for resistance and high manifestation of valuable traits. The study of leaf rust resistance in 49 common wheat varieties was carried out in the field against the natural pathogen background and under laboratory conditions using single-pustule isolates with virulence to Lr9 and Lr24. It has been shown that the varieties carrying alien genes Lr6Agi2 (Tulaikovskaya 10) and Lr6Agi1 (Voevoda) were resistant to leaf rust infection both in the field and in the laboratory. Varieties KWS Buran, KWS Akvilon, KW 240-3-13, and Etyud producing crop yields from 417 to 514 g/m2 comparable to the best standard variety Sibirskaya 17 can be reasonably used as Lr24 resistance gene donors under West Siberian conditions. Omskaya 44 variety showing crop yield of 440g/m2 can be used as a donor for Lr19 and partially effective Lr26. Varieties Tuleevskaya and Altayskaya 110 with Lr9 in their genomes are recommended for the development of resistance gene-pyramided genotypes. The highest protein and gluten contents were observed in the CS2A/2M sample, while KWS Buran, Altayskaya 110, Volgouralskaya, and KWS Akvilon showed the lowest values. Varieties CS2A/2M, Tulaikovskaya 10, Pavon, and Tuleevskaya were ranked the highest in micro- (Cu, Mn, Zn, Fe) and macronutrient (Ca, Mg, K) contents among the common wheat samples from the collection, while the lowest values for most elements were observed in KWS Buran, Novosibirskaya 15, and Volgouralskaya. Winter varieties demonstrating leaf rust resistance against the infectious background typically carry adult plant resistance genes (Lr34, Lr12, and Lr13), particularly combined with the juvenile Lr26 gene. The presence of Lr41 in a winter type line (KS 93 U 62) allowed it to maintain resistance against a leaf rust pathogen clone kLr24, despite the presence of Lr24 in the genotype. Varieties Doka and Cheshskaya 17 may act as donors of resistance genes Lr26 + Lr34 and Lr9 + Lr12 + Lr13 + Lr34, as well as sources of dwarfing without losses in winter hardiness and yield under West Siberian conditions.
The problem of functional diagnosis of technical systems described by linear dynamic models under disturbances is considered. For solving the problems of detection, isolation and identification of ...faults, a method based on sliding mode observers is used. Modifications of this method for relaxing the implementation constraints in comparison with the well-known results and also for reducing the complexity of diagnostic tools are proposed.
This paper proposes a method for diagnosing linear dynamic systems described by discrete-time models with exogenous disturbances based on interval observers. Formulas are derived to construct an ...interval observer producing two values of the residual as follows: if zero is between these values, then the system has no faults to be detected by the observer. The case where zero does not belong to the interval between these values is qualified as the occurrence of a fault. The theoretical results are illustrated by an example.
The problem of virtual sensor design is described for a given technical system equipped with sensors to measure the components of its state vector. Such sensors can be useful in cases where existing ...physical sensors are insufficient or a failed sensor needs to be replaced. The use of additional physical sensors to achieve the necessary result may require extra costs; in addition, the reliability of such sensors is usually low. The authors state and solve the problem of designing virtual sensors for technical systems described by dynamic models representing nonsmooth nonlinearities (dry friction, play, hysteresis, and saturation) under external perturbations. Relations are presented that enable the design of a sensor of minimum complexity that can estimate given state vector components of the system. A sensor synthesized in this way will be insensitive or minimally sensitive to external perturbations and can complement existing physical sensors or replace a failed physical sensor. Theoretical principles are illustrated using the design of virtual sensors for a known three-tank system as an example. The conducted Matlab-based simulation confirms the accuracy of computations and design. The obtained results can be applied in the design of fault-tolerant systems.
