ALGORITHM OF MULTIHARMONIC DISTURBANCE COMPENSATION IN LINEAR SYSTEMS WITH ARBITRARY DELAY: INTERNAL MODEL APPROACH

Subject of Research. The problem of multiharmonic disturbance compensation for the class of linear time-invariant plants with known parameters and delay is considered. Method. The disturbance is presented as unmeasurable output of linear autonomous model (exosystem) with known order and unknown parameters. The problem is resolved with the use of parametrized representation of disturbance designed by means of exosystem state observer and predictor of this state that finally enables applying certainty equivalence principle. In order to remove undesirable influence of delay a modified adaptation algorithm is created. The algorithm is based on augmentation of the plant state vector and generates advanced adjustable parameters for control. As distinct from widespread approaches, the proposed algorithm does not require identification of disturbance parameters and gives the possibility to remove such restrictions as adaptation gain margin and time delay margin. Main Results. Simulation results obtained in MATLAB/Simulink environment are presented to demonstrate the performance of proposed approach. Results illustrate the boundness of all signals in the closed-loop system and complete compensation of harmonic signal. It is shown that the proposed idea makes it possible to increase the adaptation gain for different delays without system stability loss. Practical Relevance. The algorithm of adaptive compensation is recommended for the use in such problems as: the problem of control for active vibration protection devices wherein several dominating harmonics can be taken from the spectrum of vibration signal; the problems of control of robotics systems with periodical behavior; the problems of ship roll compensation; the problems of space plants control in the presence of uncontrollable rotation

Randomized Controlled Parallel-Design Clinical Study of the Efficacy and Safety of Intranasal Interferon gamma in Treatment of Influenza-Like Infections

Background: Influenza is a highly variable infection that can cause fatal complications. Universal approaches, such as general stimulation of the immune system to activate its natural antiviral capacities, seem to be a rational measure. Methods: A total of 410 patients with influenza-like infections (ILI) were randomly assigned to one of three treatment groups and one control group. Interferon gamma (IFN-γ) was administered by intranasal introduction of 1 to 3 drops into each nostril 5 times per day daily for 5 days. The first dose of investigational medicine was given within 48h of the onset of the influenza-like symptoms. One drop of the solution contains 1,000 IU of active substance. All patients received basic complex therapy without any antiviral or immunomodulating agents. The patients were followed up for 7 days. Treatment efficacy was evaluated by the mean duration of symptoms (MDS), the period of viral antigen detection (VAD) measured after 1-2 and 4-5 days of treatment, and the incidence of complications. We used conventional indicators to evaluate the safety of IFN-γ in the treatment of ILI. Results: The administration of 2 or 3 drops of IFN-γ in each nasal passage led to better outcomes manifested in the considerable (P<0.05) reduction of all acute respiratory symptoms, and therefore to a more rapid recovery. In these treatment groups, statistically significant decreases for MDS values, VAD period, and incidence of complications were registered. Intranasal IFN-γ in complex therapy of ILI was considered to be well tolerated and safe

Ge quantum dot arrays grown by ultrahigh vacuum molecular beam epitaxy on the Si(001) surface: nucleation, morphology and CMOS compatibility

Issues of morphology, nucleation and growth of Ge cluster arrays deposited by ultrahigh vacuum molecular beam epitaxy on the Si(001) surface are considered. Difference in nucleation of quantum dots during Ge deposition at low (<600 deg C) and high (>600 deg. C) temperatures is studied by high resolution scanning tunneling microscopy. The atomic models of growth of both species of Ge huts---pyramids and wedges---are proposed. The growth cycle of Ge QD arrays at low temperatures is explored. A problem of lowering of the array formation temperature is discussed with the focus on CMOS compatibility of the entire process; a special attention is paid upon approaches to reduction of treatment temperature during the Si(001) surface pre-growth cleaning, which is at once a key and the highest-temperature phase of the Ge/Si(001) quantum dot dense array formation process. The temperature of the Si clean surface preparation, the final high-temperature step of which is, as a rule, carried out directly in the MBE chamber just before the structure deposition, determines the compatibility of formation process of Ge-QD-array based devices with the CMOS manufacturing cycle. Silicon surface hydrogenation at the final stage of its wet chemical etching during the preliminary cleaning is proposed as a possible way of efficient reduction of the Si wafer pre-growth annealing temperature.Comment: 30 pages, 11 figure

Formation of SnO and SnO2 phases during the annealing of SnO(x) films obtained by molecular beam epitaxy

SnO and SnO2 films were obtained on the SiO2 surface by the molecular-beam epitaxy method. The initial film

Role of angiotensin II and neuroendocrine factors in immunological regulation in patients with coronary heart disease: prospective cross-sectional study

BACKGROUND: Among chronic noncommunicable diseases, cardiovascular diseases, particularly coronary heart disease (CHD), are the leading cause of death. The rennin-angiotensin-aldosterone system plays an important role in CHD development and progression; however, its role in the regulation of immunoneuroendocrine interactions requires further analysis. OBJECTIVE: To study the relationship between angiotensin II (AT II) and molecular regulators of the activity of whole blood mononuclear cells (MNCs) in patients with angina pectoris. MATERIALS AND METHODS: This cross-sectional study enrolled 65 patients with exertional angina aged 45–67 years, including 19 apparently healthy individuals. The levels of interleukins (ILs), transforming growth factor-β1 (TGF-β1), prostaglandin E2 (PG E2), serotonin, thyroid-stimulating hormone (TSH), and AT II in the blood serum were determined. In MNCs, the concentrations of protein kinases FAK, JNK, p38, and ERK, signal transducers, and activators of transcription (STAT 3, 5A, and 6) were determined. RESULTS: In patients with coronary artery disease, the production of TGF-β1 increased by 7.2% (p=0.00001), AT II by 136.9% (p=0.0001), serotonin by 129.0% (p=0.00001), IL-18 by 92.5% (p=0.00001), TSH by 51.7% (p=0.0012), ERK protein kinase content by 86.4% (p=0.0001), JNK by 56.8% (p=0.0001), and FAK by 55.3% (p=0.00002). The levels of IL-15 also decreased by 38.1% (p=0.0001), PG E2 by 39.5% (p=0.0001), and STAT3 by 52.5% (p=0.0001). CONCLUSION: The nature of the identified relationships among the analyzed factors allows us to consider AT II as a factor that ensures adaptive coupling of immune and neuroendocrine regulatory mechanisms in patients with coronary artery disease, contributing to a change in the balance between macrophages and T-helper types 1 and 2

Elastically stressed pseudomorphic SiSn island array formation with a pedestal on the Si(1 0 0) substrate using Sn as a growth catalyst

The Sn-rich islands with a Si pedestal on the Si(1 0 0) substrate were obtained by the molecular-beam epitaxy technique. Initially, Sn films of different thicknesses were formed on the Si surface and then annealed to create the Sn island arrays, which were used as nanoobject growth catalysts. The Sn island density reaches up to 6 × 109 cm−2, whereas the Sn island sizes are changed in the range of 40–180 nm. The Sn-rich islands with the Si pedestal were first appeared after the Si deposition on the surface with the Sn islands in the temperature range of 300–450 °C. The new obtained nanostructures have the island density up to 4 × 108 cm−2 and the island sizes, which varied from 60 to 400 nm. The island growth with the pedestal occurred on the vapor-liquid-solid mechanism. The chemical analysis of the samples carried out using the energy-dispersive X-ray spectroscopy indicated the presence of the Sn-rich region on the top of nanoobjects. The intense photoluminescence from the Sn-rich islands with the Si pedestal was detected. The photoluminescence peak takes place at 1.55 µm