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This paper considers a tracking system developed for a full-actuated manipulator with flexible joints under the following assumptions: torques are control actions, and current loop dynamics are not considered; the mass-inertial characteristics of the manipulator and other parameters are not exactly known; the external matched and unmatched disturbances act on the system, and matched disturbances are not smooth; the derivatives of the reference actions are achievable but are unknown functions of time; the set of sensors is not complete. Based on the representation of the control plant model in a block form of input–output with respect to mixed variables (functions of state variables, external influences and their derivatives), we have developed a combined control law for the case where the control matrix contains additive uncertain elements. In addition, we have designed the mixed variable observers of the smallest possible dimension with piecewise linear corrective actions for two cases: (i) only the generalized coordinates of the manipulator are measured; (ii) only the angular positions and velocities of the motors are measured. It is shown that in a closed-loop system with dynamic feedback, a given tracking error stabilization accuracy is provided in the conditions of incomplete information. We presented the results of numerical simulation of these algorithms for a single-link manipulator.

The novelty of the work lies in the creation and study of the physical and biological properties of biodegradable polymer coatings for stents based on poly(lactic-co-glycolic acid) (PLGA). Polymer coatings are capable of prolonged and directed release of molecules with a high molecular weight, in particular, protein molecules of prourokinase (m.w. 54 kDa). A technology has been developed to create coatings having a relative elongation of 40% to 165% and a tensile strength of 25-65 MPa. Coatings are biodegradable; the rate of degradation of the polymer in an isotonic solution varies in the range of 0.05%-1.0% per day. The created coatings are capable of controlled release of the protein of prourokinase, while about 90% of the molecules of prourokinase retain their enzymatic activity. The rate of release of prourokinase can vary from 0.01 to 0.08 mg/day/cm

The present work is related to the microscopic studies of the morphology of the planar and inner part of silicon nanowires arrays before and after immobilization with a natural nanomaterial, Dps protein of bacterial origin. Silicon nanowires were formed by metal-assisted wet chemical etching. To obtain the recombinant protein, Escherichia coli cells were used as excretion strain and purification were carried out using chromatography. The combination of silicon nanowires with protein molecules was carried out by layering at laboratory conditions followed by drying under air. The resulting hybrid material was studied by high-resolution scanning electron microscopy. Studies of the developed surface of the nanowires array were carried out before and after combining with the bioculture. The initial arrays of silicon wireshave a sharp boundaries in the planar part and in the depth of the array, transition layers are not observed. The diameter of the silicon nanowires is about 100 nm, the height is over a micrometer, while the distances between the nanowires are several hundred of nanometers. The pores formed in this way are available for filling with protein during the immobilization of protein.The effectiveness of using the scanning electron microscopy to study the surface morphology of the hybrid material “silicon wires – bacterial protein Dps” has been demonstrated. It is shown that the pores with an extremely developed surface can be combined with a bio-material by deposition deep into cavities. The protein molecules can easily penetrate through whole porous wires matrix array. The obtained results demonstrate the possibility of efficient immobilization of nanoscaled Dps protein molecules into an accessible and controllably developed surface of silicon nanowires.

In this paper, we consider the convey-crane system, which can transport loads for industrial purposes. The mathematical model, describing the motion of convey-crane, is presented by a Lagrangian mechanical system of nonlinear equations with two degrees of freedom and one control action. It is supposed that the rope has no mass, its stiffness is not taken into account, and there is no friction in the joints. The stabilization problem of the desired convey-crane position is posed underuncertain mass inertia characteristics, an action of non-smooth bounded disturbances and incomplete measurements. Based on the passivity property, the control law with linear and sigmoidal parts is constructed for the solution of the problem. The only measurement of the convey-crane position is available without a noise in the measurements. We use the low order observer with sigmoidal corrective action to obtain the needed velocity estimates for the control law. It is shown that the using of sigmoidal function as a prelimit realization of sign-function provides disturbances invariance with the given accuracy. With respect to the smoothness and boundness, sigmoidal function helps to avoid overshoot in the transient responses and excessive consumption of control resources. Moreover, unlike the sign-function, a sigmoidal function is realized in the electromechanical systems with actuator dynamics, in which the physical restrictions on the forces and general moments are posed. The constructed control law with linear and sigmoidal parts is simulated for the convey-crane system in MATLAB- Simulink. The classical PD-controller is simulated too for the purpos e of comparison. The results of modeling are proved the effectiveness of the proposed approach.

The problem of the synthesis of a tracking system for electromechanical control objects is considered when measuring only the generalized coordinates of the mechanical subsystem. It is assumed that external and parametric perturbations act on the system. Assuming the smoothness of external perturbations and uncertainties, the mathematical model of the control object is presented in the form of a joint block form of controllability and observability relative to the coordinate basis of mixed variables (functions of state variables, external influences, and their derivatives). Based on these conditions of the joint block form of parametric uncertainty of the matrix before the control actions, a procedure for decomposition synthesis of the basic law of discontinuous control has been developed. The basic control law ensures exponential convergence of the generalized coordinates to the reference signals. To obtain estimates of the mixed variables used in the feedback, a method for synthesizing an observer of a lower order state with large coefficients is proposed, in which the principle of complete decomposition is implemented. The results of numerical modeling of the developed algorithms for a three-link manipulator operating in a cylindrical workspace under incomplete information conditions are presented.

In recent years, laser micromachining has made impressive gains in terms of accuracy, scalability and surface finish. Moreover, the availability of femtosecond lasers yields ablation without melting. Surfaces processed in this fashion exhibit less structural damage and are expected to have a higher damage thresholds. In this paper we will review several case studies of laser-microfabricated THz components. These will include corrugated waveguides for narrowband and quasi-optical mirror-like structures for broadband THz applications.

Spinel ferrite magnetic nanoparticles have attracted considerable attention because of their high and flexible magnetic properties and biocompatibility. In this work, a set of magnetic nanoparticles of cobalt ferrite doped with zinc was synthesized via the eco-friendly sol-gel auto-combustion method. Obtained particles displayed a room-temperature ferromagnetic behavior with tuned by chemical composition values of saturation magnetization and coercivity. The maximal values of saturation magnetization ~74 Am2/kg were found in cobalt ferrite nanoparticles with a 15&ndash, 35% molar fraction of cobalt replaced by zinc ions. At the same time, the coercivity exhibited a gradually diminishing trend from ~140 to ~5 mT whereas the concentration of zinc was increased from 0 to 100%. Consequently, nanoparticles produced by the proposed method possess highly adjustable magnetic properties to satisfy the requirement of a wide range of possible applications. Further prepared nanoparticles were tested with bacterial culture to display the influence of chemical composition and magnetic structure on nanoparticles-bacterial cell interaction.

In this paper, a stabilization problem of angular positions is considered for the twin rotor electromechanical system under parametric uncertainties and the presence of cross-couplings between rotors. The procedure of block synthesis of nonlinear local feedbacks and discontinuous controls is developed. This procedure allows satisfying the project restrictions on the state variables and control actions. The simulation results of the developed procedure are presented.

The paper deals with the twin rotor MIMO system, which behavior is much similar to the behavior of a real technical device – a helicopter. The tracking problem of the generalized coordinates (yaw and pitch angles) for the given trajectories is posed in the conditions of the model's parametric uncertainties and in the action of unknown external disturbances. The decomposition synthesis of the control law is performed on the basis of the block approach using non-linear S-shaped sigmoidal feedbacks. The reduced order state observer with sigmoidal corrective action is constructed to obtain the estimates of the generalized velocities when generalized coordinates are measured. It is shown that the use of sigmoidal feedback allows us to reduce the possible overshoot at the beginning of transient responses, and to provide tracking of given signals with a given accuracy invariant with respect to parametric and external disturbances without using exogenous dynamic models of external influences.

Received: 15.04.2020. Accepted: 27.06.2020. Published: 30.06.2020. An improved technology for the industrial production of K3 series vitamins based on menadion is reported. The procedure involves the Cr(VI) — promoted oxidation of the corresponding methyl-naphtahelenes with the following purification by precipitation/recrystallization. The best results were obtained under the process temperature between 20–40 °C, solution pH after dilution of MNB in a range of 5.5–5.7, and MNB content in initial solution of 25–30%.

Renewed technology has created a demand for foods which are natural in taste, minimally processed, and safe for consumption. Although thermal processing, such as pasteurization and sterilization, effectively limits pathogenic bacteria, it alters the aroma, flavor, and structural properties of milk and milk products. Nonthermal technologies have been used as an alternative to traditional thermal processing technology and have the ability to provide safe and healthy dairy products without affecting their nutritional composition and organoleptic properties. Other than nonthermal technologies, infrared spectroscopy is a nondestructive technique and may also be used for predicting the shelf life and microbial loads in milk. This review explains the role of pascalization or nonthermal techniques such as high-pressure processing (HPP), pulsed electric field (PEF), ultrasound (US), ultraviolet (UV), cold plasma treatment, membrane filtration, micro fluidization, and infrared spectroscopy in milk processing and preservation.

Simple Summary In this work, for the first time, we studied some aspects of the development of the visual system of the annual killifish (Nothobranchius guentheri) in the embryonic and postembryonic periods. The morphoanatomical features of the eye during the growth and maturation of the fish are determined. In addition, the normal histological structure of the main elements of the eye is studied. Age-related changes in the elemental composition of the lens of the eye have been studied. The data obtained make it possible to assert the important role of the visual system for the survival of fish in shallow ephemeral pools. In such environmental conditions, the efficacy of the visual system is a factor in survival and evolution. Abstract In this, work some aspects of the development of the visual system of Nothobranchius guentheri at the main stages of ontogenesis were described for the first time. It was possible to establish that the formation of the visual system occurs similarly to other representatives of the order Cyprinodontiformes, but significantly differs in terms of the individual stages of embryogenesis due to the presence of diapause. In the postembryonic period, there is a further increase in the size of the fish’s eyes and head, to the proportions characteristic of adult fish. The histological structure of the eye in adult N. guentheri practically does not differ from most teleost fish living in the same environmental conditions. The study of the structure of the retina showed the heterogeneity of the thickness of the temporal and nasal areas, which indicates the predominant role of peripheral vision. Morphoanatomical measurements of the body and eyes of N. guentheri showed that their correlation was conservative. This indicates an important role of the visual system for the survival of fish in natural conditions, both for the young and adults. In individuals of the older age group, a decrease in the amount of sodium (Na) and an increase in magnesium (Mg) and calcium (Ca) were found in the eye lens. Such changes in the elemental composition of the lens can be a sign of the initial stage of cataractogenesis and disturbances in the metabolism of lens fibers as a result of aging. This allows us to propose N. guentheri as a model for studying the structure, formation, and aging of the visual and nervous systems.

Currently, one of the most common methods for the synthesis of dispersions based on turpentine in aqueous media is the preparation of its solutions in water using multi-stage chemical and/or physical treatment. In this case, the chemical composition is selected in such a way as to ensure the complete dissolution of hydrophobic substances in water. An example of solving such a problem is the use of an aqueous solution of the following composition: gum turpentine 43.0%; oleic acid 25.0%; castor oil 18.0%; caustic soda 3.0%. However, such methods do not allow setting and controlling dimensional parameters in the final product. In addition, in many cases, such a lyosol requires the addition of stabilizers and emulsifiers, which is determined by the purpose of the synthesized lyosol. Here we show the possibility of influencing the size parameter of the resulting particles in lyosol and their resistance to sedimentation in an aqueous solution. This result is achieved by homogenization using ultrasonic dispersion of a low-concentrated aqueous solution of turpentine, bubbling with various gases and subsequent filtration of the resulting emulsion through a membrane with a suitable pore size. This approach makes it possible to obtain at least 95% of nanoparticles from the total dry matter fraction. Compounds based on such lyosols, as a rule, have immunoreactogenic properties and can be used as an adjuvant component that increases the immunogenicity of inactivated vaccines, including for veterinary use.

The authors studied the possibility of using several methods for obtaining a collagen-containing base, which is a collagen hydrate obtained using organic acids. Collagen is a unique protein and a part of a variety of connective tissues of living organisms. It has a form of a unique three-spiral structure consisting of a molecule of a specific set of amino acids. It is of great practical importance for cosmetology and medicine. Collagen is one of the most common proteins in living organisms. A significant proportion of collagen is concentrated in the skin. Known methods for obtaining a collagen product are associated with the use of organic acids for de-fibration. After processing, the collagen product has a high moisture-absorbing property. Selection of the concentration and type of organic acid makes it possible to obtain a product with the necessary characteristics of functional and technological properties. Also important that they have a positive effect on the state of the human body, as well as open the possibility of varying properties for targeted use in cosmetology and medicine. The obtained collagen substances provide a range of concentrations necessary for specific purposes, have high hydrophilicity, and create conditions for obtaining various forms (dispersions, membrane materials, and sponges) for subsequent use in the cosmetic and medical industries.

Proteins of the Dps family perform a dual function in bacterial cells. As ferritins, they protect cells from destructive effects of Fe2+ ions, while interacting with DNA they condense the genome in the absence of nutrients. The ability of Dps to self-aggregate is of a great importance. The way of genome remodelling from the condensed state to the active one is not yet known. Here, the effects of two sugar ligands on Dps interaction with DNA have been studied in vitro. For the first time it was demonstrated that D-glucuronate and D-galacturonate, but not D-glucose, can decompose the dodecameric structure of the protein and D-glucuronate stimulated the formation of binary complexes with the linear DNA fragments. As a result of flexible molecular docking, it was found that the molecules of all three sugars potentially can form clusters inside the protein cavity of Dps, but D-glucuronate and D-galacturonate were also bound in the region of intersubunit contacts of oligomer. The consequent destabilization of the intersubunit bonding network can, thus, be the main factor provoking the protein decay to the smaller oligomeric forms. Such a structural rearrangement, leading to a reduction in aggregation, may play a key role in genome decondensation during cell transition to the phase of rapid growth.

The Escherichia coli Dps protein belongs to a specific family of bacterial ferritins; it is a nanosized particle that contains an inorganic core (~5 nm in diameter) and a protein shell with a size of 8–9 nm. The protein shell consists of 12 identical subunits with the known crystal structure of a dodecamer. The composition and structure of the core have been less studied. The core formation is associated with the oxidation products of Fe2+ ions in the ferroxidase centers of the protein. Thus, Fe2O3 oxides are the main compounds of the core. However, the mineralization properties of Fe2+ ions under anaerobic conditions in vitro may indicate a more complicated composition of the core in the native Dps protein. This paper presents a technique for the preparation of purified Dps samples for ultrahigh vacuum synchrotron experiments by X-ray absorption near edge structure spectroscopy of the iron absorption edge in the soft X-ray region. The conducted synchrotron experiments have revealed the presence of both trivalent and divalent iron ions in the octahedral and tetrahedral environment of oxygen atoms in the prepared biological samples. This points to a complex ionic composition of the core even in the native Dps protein, which has been isolated from aerobically grown bacteria.

A technology for producing a new homogeneous Ti–20Nb–13Ta–5Zr alloy has been developed. It is shown that the alloy is single-phase with a β-Ti type crystal lattice. The alloy has the required mechanical properties (tensile strength of about 745 MPa). On the surface of plates and wire made of alloy, a relief of micro- and nanoscale is observed. In terms of the ability to generate reactive oxygen species and long-lived reactive protein species, the Ti–20Nb–13Ta–5Zr alloy is more preferable than nitinol. It was established that cell cultures growing on plates or wire made of Ti–20Nb–13Ta–5Zr alloy had a significant mitotic index (2%). The number of viable cells was at least 95–96% of the overall cell count. According to the results of implantation of the alloy in the form of plates or wire ring to animals, it can be concluded that the alloy is biocompatible. The morphology of the surface of the samples did not change after biological experiments. It can be assumed that the alloy Ti–20Nb–13Ta–5Zr is a material potentially suitable for medical applications.

In this paper we consider the tracking problem for a given action for a linear SISO plant, which model is presented in the input-output form. The problem is posed in the presence of noisy measurements and restrictions on the state variables and control action. The information about the derivatives of the given action is absent. The block synthesis procedure with nonlinear sigmoidal functions in feedbacks is developed for the solution of this problem. Whereas the estimation of state variables and measurement filtering are performed by using Kalman-Bucy filter.

In this paper, the procedure of feedback decomposition synthesis, providing stabilization of output variables with the given accuracy is developed for a nonlinear control plant which model contains external unmatched disturbances and is presented in the input-output block form with stable inner dynamic. The approach provides restrictions on state variables during a control process by using smooth, bounded S-shaped sigma-functions as local feedbacks and does not require parametric certainty of the control plant and introduction of dynamic models of external disturbances.

The paper deals with block design of control system of gripper position of a manipulator under conditions of uncertainty of load mass and incomplete measurements. Restrictions on the state variables of the electromechanical system in the controlt process are provided by use of S-shaped smooth sigma-functions in local feedbacks and corrective actions of the states observer.

Implementation of non-waste technologies at the poultry establishments supposes the involvement of by-products of slaughter of birds, in particular, the blood as a source of protein and unique organic iron. For the feasibility of reasonable approaches to the possible use of birds' blood in the production of technologically acceptable emulsions there was studied and identified by the method of PCR analysis the species composition of microflora in the process of blood collection and storage, as also the environment of the slaughterhouses, there was considered the dynamics of the growth of microorganisms and measures for its limitation.

The EN 1435 standards and State Standard GOST 7512 are compared and corrections to State Standard GOST 7512 are recommended.

Dps is a multifunctional homododecameric protein that oxidizes Fe2+ ions accumulating them in the form of Fe2O3 within its protein cavity, interacts with DNA tightly condensing bacterial nucleoid upon starvation and performs some other functions. During the last two decades from discovery of this protein, its ferroxidase activity became rather well studied, but the mechanism of Dps interaction with DNA still remains enigmatic. The crucial role of lysine residues in the unstructured N-terminal tails led to the conventional point of view that Dps binds DNA without sequence or structural specificity. However, deletion of dps changed the profile of proteins in starved cells, SELEX screen revealed genomic regions preferentially bound in vitro and certain affinity of Dps for artificial branched molecules was detected by atomic force microscopy. Here we report a non-random distribution of Dps binding sites across the bacterial chromosome in exponentially growing cells and show their enrichment with inverted repeats prone to form secondary structures. We found that the Dps-bound regions overlap with sites occupied by other nucleoid proteins, and contain overrepresented motifs typical for their consensus sequences. Of the two types of genomic domains with extensive protein occupancy, which can be highly expressed or transcriptionally silent only those that are enriched with RNA polymerase molecules were preferentially occupied by Dps. In the dps-null mutant we, therefore, observed a differentially altered expression of several targeted genes and found suppressed transcription from the dps promoter. In most cases this can be explained by the relieved interference with Dps for nucleoid proteins exploiting sequence-specific modes of DNA binding. Thus, protecting bacterial cells from different stresses during exponential growth, Dps can modulate transcriptional integrity of the bacterial chromosome hampering RNA biosynthesis from some genes via competition with RNA polymerase or, vice versa, competing with inhibitors to activate transcription. This work was funded by: 1. Russian Scientific Foundation (grant 14-14-00985, http://rscf.ru/node/8, PI: ONO, team members: SSA, MNT, USS (sample preparation, MiSeq sequencing, data analysis and evaluation)); 2. Russian Foundation for basic research (grant 16-34-01044, http://www.rfbr.ru/rffi/eng, PI: USS, reporter assays); 3. HHMI International Early Career Scientist Program (55007424, FAK) (http://www.hhmi.org/, FAK, HiSeq Illumina sequencing); 4. European Research Council grant agreement (335980_EinME, https://erc.europa.eu/, FAK, HiSeq Illumina sequencing); 5. Russian Foundation for Basic Research 16-04-01570 (http://www.rfbr.ru/rffi/eng) (PI ONO).

Seventy-eight promoter islands with an extraordinarily high density of potential promoters have been recently found in the genome of Escherichia coli. It has been shown that RNA polymerase binds internal promoters of these islands and produces short oligonucleotides, while the synthesis of normal mRNAs is suppressed. This quenching may be biologically relevant, as most islands are associated with foreign genes, which expression may deplete cellular resources. However, a molecular mechanism of silencing with the participation of these promoter-rich regions remains obscure. It has been demonstrated that all islands interact with histone-like protein H-NS — a specific sentinel of foreign genes. In this study, we demonstrated the inhibitory effect of H-NS using Δhns mutant of Escherichia coli and showed that deletion of dps, encoding another protein of bacterial nucleoid, tended to decrease rather than increase the amount of island-specific transcripts. This observation precluded consideration of promoter islands as sites for targeted heterochromatization only and a computer search for the binding sites of 53 transcription factors (TFs) revealed six proteins, which may specifically regulate their transcriptional output.

In the Two Beam Accelerator (TBA), wakefield power extractors which extract high power RF from a high current beam are used to power high gradient accelerating structures. A dielectric‐based Wakefield Power Extractor (DWPE) is one option in addition to the metallic structures considered previously, like the CLIC PETS (Power Extraction and Transfer Structure). 7.8 GHz and 26 GHz DWPE prototypes have been successfully built and tested at the Argonne Wakefield Accelerator (AWA) facility. We are currently designing an X‐band version for a potential application with the CLIC beam. In this article, we report on test results of the 26 GHz DWPE and the preliminary design of the X‐band structure. Future plan and possible difficulties in the development of DWPEs are also discussed.

We report on a design of a TM‐mode based metamaterial‐loaded waveguide. Network analyzer measurements demonstrated a left‐handed propagation region for the TM11 mode at around 10 GHz. A beamline experiment was performed with the metamaterial‐loaded waveguide. In this experiment, a 6 MeV electron beam passes through the waveguide and generates a wakefield, via the Cherenkov radiation mechanism. We detected a signal in the left‐handed frequency band at 10 GHz. This is an indirect demonstration of reverse Cherenkov radiation as discussed in several papers. Cherenkov radiation in artificially constructed materials (metamaterials, MTM) can provide unusual, engineered features that can be advantageous for particle detector design.

Measurement of Cherenkov radiation (CR) has long been a useful technique for charged particle detection and beam diagnostics. We are investigating metamaterials engineered to have refractive indices tailored to enhance properties of CR that are useful for particle detectors and that cannot be obtained using conventional media. Cherenkov radiation in dispersive media with a large refractive index differs significantly from the same effect in conventional detector media, like gases or aerogel. The radiation pattern of CR in dispersive metamaterials presents lobes at very large angles with respect to particle motion. Moreover, the frequency and particle velocity dependence of the radiated energy can differ significantly from CR in a conventional dielectric medium.