The article presents data on the feasibility of the concept of a high-efficiency seed cleaner with the consistent use of the air flow in aspiration and the multi-tier placement of the sorting grids ...in grating mills. As a result of modeling, the directions for further improvement of air-screen seed cleaning machines have been identified: an increase in the proportion of sorting grids in the mills up to 70 ... 80% and an increase in the speed of the air flow in the channel of the pre-filter cleaning up to 8.0 m / s. Experiments have established the competence of using mathematical modeling of airflow in the pneumatic system with the use of a finite-volume method for solving hydrodynamic equations for substantiating the basic parameters of the pneumatic system.
In view of the high prevalence of hypertension (HTN) among Russian population, it becomes extremely important to meet the criteria for the medical care quality within the periodic examinations for ...this group of patients.
Aim
. To assess the quality of follow-up monitoring of the adult population with grade 1-3 hypertension, with the exception of resistant hypertension (RH), by primary care physicians in different Russian regions.
Materials and methods
. As part of working visits of the expert group from the National Medical Research Center for Therapy and Preventive Medicine in 38 Russian regions in the period from February 1, 2020 to December 15, 2020, an analysis of ambulatory records of patients with grade 1-3 hypertension was carried out. A total of 3614 ambulatory medical records (AMRs) were analyzed, of which the grade 1-3 hypertension, with the exception of RH, was revealed in 764 ones. The analysis of records was carried out using an original checklist. Statistical processing was carried out using the software package IBM SPSS Statistics 20 (USA) and Microsoft Office Excel 2016 (USA).
Results
. An analysis of 764 AMRs was performed. The mean age of patients was 63,9-11,2 (women, 64,7-11,3 years; men, 62,7-10,9 years). The majority (58,9%) of participants were women. Follow-up monitoring was established in a timely manner in 450 people (58,9%) of patients, of which there were 189 men (42%) and 261 women (58%). In 87,9% (n=672) of cases, the diagnosis formulation met the established clinical guidelines criteria. In 36 cases (4,7%), there was no evidence in favor of hypertension according to the current clinical guidelines. In 21,1% (n=161) of cases, the minimum recommended periodicity of visits was not observed. In last visits of 323 patients, the blood pressure did not reach the target values. AMRs did not contain information on low-density lipoprotein cholesterol (LDL-C) in 91б4% of cases (n=698). Among patients with a known level of LDL-C, the target values were achieved only in 15,2% of cases (n=10).
Conclusion
. Our analysis revealed the insufficient quality of outpatient medical care to hypertensive patients within the periodic examinations. Proposals are created for monitoring and measures to improve the quality of care for this category of patients.
Temperature dependence of dielectric properties of nematic liquid crystals are investigated for two types of devices: wide temperature range liquid crystal displays and capacitor temperature sensor.
A technology for producing a nanocomposite based on the borsiloxane polymer and aluminum oxide nanoparticles (Al2O3 NPs) has been developed. Nanocomposites containing 0.001, 0.01, and 0.1 wt% Al2O3 ...NPs have been created. It has been shown that the nanocomposite with any content of Al2O3 NPs did not lose the main rheological properties of borsiloxane. The resulting nanomaterial is capable of generating reactive oxygen species (ROS) such as hydrogen peroxide and hydroxyl radicals. The rate of ROS generation increases up to 3 times with an increase in the concentration of Al2O3 NPs. It has been shown that the nanocomposite leads to the formation of long-lived reactive protein species, and is also the reason for the appearance of such a key biomarker of oxidative stress as 8-oxoguanine in DNA. The intensity of the process increases with an increase in the concentration of Al2O3 NPs. Moreover, it was found that bacterial cells adhere to the surfaces of the nanocomposite (reduces the number of bacteria on the substrate by 39 times), and the nanocomposite can detach bacterial cells not only from the surfaces, but also from wetted substrates. The ability to capture bacterial cells is primarily associated with the properties of the polymer; they are weakly affected Al2O3 NPs. The nanocomposite is non-toxic to eukaryotic cells, the surface of the nanocomposite is suitable for eukaryotic cells for colonization. Due to unique physical properties, low cytotoxicity and antimicrobial action, this nanocomposite can be used in medicine and prosthetics.
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•A new composite based on borsilaxane and aluminum oxide NP has been obtained.•The mechanical and physicochemical properties of the composite have been studied.•Composite inhibits bacteria growth and does not affect growth of animal cells.•The antibacterial effect is probably based on the ability to damage biopolymers.•The composite can be used in the food or textile industry.
Composites in a wide concentration range of 0-0.6 wt% based on a nematic liquid crystal mixture and CdS quantum dots doped with manganese ions (Mn 6%) are presented. The effect of the CdS:Mn quantum ...dots on the phase diagram and electronic structure of composites was studied using differential scanning calorimetry and fluorescence analysis. Nonmonotonic concentration-dependent changes in the clearing point, which correlate with the fluorescence quenching behavior of the main CdS:Mn peak, were found. Dielectric spectroscopy and electro-optic studies revealed a corresponding increase in the dielectric permittivity anisotropy and birefringence in the 0.2-0.4 wt% range, where thermodynamic changes occur. The initiating factors behind this effect are supposed to be the self-assembly of quantum dots, and the distortion of the orientation order of liquid crystal molecules at a higher mass concentration of quantum dots.
In liquid crystal/quantum dots composites, a nonmonotonic increase in the electrooptical performance with a change in dopant concentration was found. The changes are explained within the framework of the self-organization hypothesis of quantum dots.
Water-soluble forms of fullerene C
60
possess unique physicochemical and biological properties, making them promising candidates for the development of various drugs in the fields of medicine and ...veterinary science. Of particular interest are studies on the synthesis and characterization of C
60
fullerene derivatives with biogenic additives such as amino acids and peptides. This review focuses on different approaches to the synthesis of amino acid derivatives of fullerene C
60
and their promising biomedical applications.
When modeling the dynamic properties of an unmanned aerial vehicle (UAV) and an automatic control system (ACS), it is often necessary to take into account factors such as the lack of rigidity of the ...aircraft structure, the influence of control and destabilizing factors, which leads to an increase in the order of the model under study. The known numerical and analytical methods do not allow us to obtain general solutions for the variable parameters of the high-order system under study, and at the same time provide the required amount of error and computational costs. A method is developed to model the dynamic properties of UAVs and high-order control systems based on the spectral method, the linear approximation by parts of the input control actions and the spectrum of the system's output signal. An example of using the technique to model the dynamic properties of different orders ACS UAVs (from 1 to 10) with different types of inertia is considered. Based on the analysis of errors in the calculation of the transition process, the effectiveness of the method for analyzing high-order systems is shown based on the required computational costs.
The use of a formation consisting of adaptive autonomous mobile agents allows solving a wide range of tasks that are often beyond the capabilities of individual agents. A multi-agent formation is a ...complex high-order dynamic system, so analyzing the stability of such a system is a complex task. At present, the problem of estimating the stability of a formation formed by substantially nonlinear high-order agents with variable dynamic parameters is not sufficiently considered. This task is particularly important for a formation that is affected by complex unstable environmental conditions, in particular for the formation of unmanned aerial vehicles (UAVs). A method for analyzing the stability of formations of nonlinear agents with different types and orders of transfer function has been developed for studying information exchange in UAV networks. The new approach is based on the use of the Popov frequency criterion and the piecewise linear approximation of the hodograph. A computational experiment was performed to analyze the stability of a formation with transfer functions of various types and orders from the 1st to the 10th. The conducted studies revealed a significant difference in the calculated boundary coefficients of formation stability in the linear and nonlinear modes, which confirms the need to analyze the nonlinear stability under the influence of strong destabilizing influences on the formation.
Creation of reliable and efficient flying ad-hoc networks (FANET) requires detailed development of the model of the physical layer of data transmission, determined by the conditions of operation of ...the networks. The problems of well-known software simulators of communication networks are the simplified nature of the physical layer, as well as the inability to obtain specific analytical solutions in the process of simulation. The hierarchical model of formation of information signals which allows to represent various types of communication channels and the channel-forming equipment, for providing their analytical description and the further analysis is developed. The model allows to describe communication channels between UAVs and (or) ground control centers taking into account the effects of attenuation, intersymbol interference, multipath propagation of signals; schemes of terminal and intermediate network equipment with linear and nonlinear signal conversion; circuits with forward regulation, backward regulation and combined regulation; circuits with multi-channel signal generation and processing, as well as cross-links between channels. Analytical expressions of the transfer function of the generalized hierarchical model for an arbitrary number of disclosed levels of hierarchy are obtained. An example of the presentation and study of the UAV transmitter circuit on the basis of a hierarchical model of signal formation is considered.
When modeling Automatic Control Systems (ACS) of an unmanned aerial vehicle (UAV), it is often necessary to take into account the nonlinearity of an aircraft's reaction when the controls drift, as ...well as the strong influence of various destabilizing factors that make the system go out of linear mode. When known analytical and numerical methods are used to analyze dynamic systems, it is problematic to obtain general solutions that are valid for the variable parameters of the system under study and, at the same time, provide the required error value. A method has been developed to model dynamic processes in automatic non-linear UAV control systems based on linear approximation by parts and crosslinking of partial solutions with consideration of the initial conditions. An example of using the technique to model the transition characteristics of an ACS UAV with a single non-linear link is considered. Based on the analysis of errors in the calculation of the transition process, the effectiveness of the proposed approach is shown.
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