Ultrasonic sensor for UAV flight navigation

Ultrasonic transducers were utilized for the design and development of an alternative method for flight instrumentation measurement of the velocity of unmanned air vehicles (UAVs). Current methods have been deemed to have significant shortcomings, such as the need for GPS thus leading to indoor UAV operations being incapable of velocity sensing. The proposed concept is developed from the utilization of ultrasonic transit-time flowmeters. A test bench has been produced to measure the accuracy and confirm the validity of the concept. Two key design variables were determined - the optimal transducer mounting configuration and the optimal angle of incidence for the transducer mountings. The mounting configurations were analyzed from common transit-time flowmeter sensor configurations and were tested using both CFD and acoustic simulations. The findings are presented and correlated based on these simulations and it was determined that a V-method configuration was the optimal choice. The correct angle of incidence was determined by an experimental methodology. The time-of-flight outputted from the transducers was compared to the calculated ideal value, and the findings revealed that an angle of 30° was the most accurate for the reflection of the emitted wave. The experimentation was conducted with a specially designed test bench and associated electronic hardware located in a wind tunnel. The test results have provided conclusive evidence that the overall design can produce accurate results comparable with current instrumentation sensors

Analysis of mechanical power flow in an electric drive operating under vibration conditions

This paper discusses the analysis of mechanical power flow in an electric motor drive operating under variation of conditions. The drive system vibration generates the oscillation in the supplied active power which can reduce performance of the system and increase the actual load on the shaft. It is shown that the vibration damper installation significantly decreases the oscillations in mechanical power flow on the motor shaft and improves characteristics of the system operation. The paper provide analysis of two models of the electric drive installed on the platform - the system which is quipped with vibration dampers and without

PLASMONIC EFFECTS IN THIN FILMS OF MgAl2O4

Thin films of ceramics MgAl2O4 on Al2O3 and SiO2 substrates are doped with Cu2+ ions with a fluence of 1x10-17 cm-2. The optical properties of the obtained samples are investigated. The films on the Al2O3 substrate have an SPR band from copper plasmonic nanoparticles in the thin surface layer.Исследование выполнено при финансовой поддержке РФФИ и Свердловской области в рамках научного проекта № 20-42-660012

A concept for an ice detection system on overhead power lines, theory and practical results

The detection of the mechanical load of high voltage overhead power lines caused by ice is a crucial point for decisions to activate de-icing and for monitoring of high current based de-icing procedures. This paper reports about solutions for ice load and high current load monitoring by wireless sensors at overhead power lines of distribution grids of 110 kV level voltage and more. A theoretical methodic of calculating of the sag of the conductors depending on the ice load and on the elevated temperature due to Joules loss is implemented into the algorithms of the sensor system. The contribution shows the practical realization of such sensors and of theoretical methods by practical results. It reports the results of a field tests at a real distribution grid of 110 kV voltage level in different weather conditions

Severe parasympathicotonia in men with hypertension is accompanied by an increase in the chronic venous diseases’ signs

Aim. To study the relationship of subjective and objective signs of chronic venous diseases (CVD) with the state of the autonomic nervous system (ANS) in men with arterial hypertension (AH).Material and methods. The object of the study were 74 men with AH at the age of 30-50 years with SBP level 148 (144-155) mm Hg. and DBP 101 (92-108) mm Hg. Two groups of 20 people were selected with the extreme parameters of vegetative index (Kerdo index).Results. The most common complaints in patients with severe parasympathicotonia were pain in the legs and fatigue when walking, cramps in the calf muscles, oedema and sural trophic disorders. An objective examination of patients with severe vagotonia revealed a more frequent occurrence of the leading symptom of CVD — oedema.Conclusion. AH with severe parasympathicotonia in men 30-50 years old is characterized by an increase in the frequency of subjective and objective signs of CVD, which indicates the role of ANS in the development of CVD in AH

Peculiarities of the reaction of the lower limbs venous blood flow to the orthostatic test in men with arterial hypertension

A comparative analysis of the dynamics of lower limb vein angioscopy parameters in case of orthostasis between male patients (age 30–50 years) with arterial hypertension (test group – 60 people) and normal arterial pressure (control group – 27 people) was made. Orthostatic sample in all examined patients was characterized by a reliable increase in the diameter and area of vein section at a decrease in blood flow rate. However, in patients with hypertension the increase in the area of vein section was significantly less than in the control group. In orthostasis, the drop in blood flow rate in the total femoral vein was lower in men with hypertension than in men in the control group. In the great saphenous vein, a larger decrease in blood flow velocity was recorded than in the control group. In hypertension, no increase in the number of refluxes was recorded in orthostasis. Thus, hypertension in men is characterized by altered reaction of venous blood flow to orthostasis in both deep and saphenous veins

Comorbidity of hypertension and chronic venous disease in men

Aim. To study the clinical manifestations and characteristics of lower extremity chronic venous disorders (CVD) in working-age men with hypertension (HTN).Material and methods. The study included 74 men with HTN at the age of 30-50 years and 41 men without HTN. HTN duration and regularity of antihypertensive medication intake were studied. We analyzed complaints and objective signs associated with CVD, their severity, structural and functional parameters of superficial, deep and perforator veins of the lower extremities using the triplex ultrasound. The prevalence and severity of cardiovascular risk factors among patients with HTN and CVD and patients with HTN and without CVD were analyzed.Results. Men aged 30-50 with HTN showed a high prevalence of complaints (68%) associated with CVD: evening heaviness and fullness in the legs; pain decrease at rest; a combination of pain, spasm and swelling in long-time standing. Objective signs of CVD were recorded in 83,8% of men with HTN (most often — telangiectasia (38%) and swelling (24%)). Men with HTN were diagnosed with more severe manifestations of CVD than men without HTN. In patients with HTN, episodic pain and evening perimalleolar swelling were 1,8 and 4 times more likely, respectively, than in men without HTN. The presence of CVD and HTN was not associated with cardiovascular risk factors. HTN in men was characterized by a large-diameter veins, pathological reflux, vein tortuosity, the presence of thrombotic masses and postthrombotic lesions. In patients with HTN, along with an increased blood flow velocity in the deep and perforator veins of the lower leg, a low velocity in the deep femoral veins was observed. This is the evidence of venous insufficiency even at rest. Orthostasis in men with HTN increased the frequency of reflux in superficial veins by 2-4 times, which proves latent venous insufficiency.Conclusion. HTN is characterized by an increase in the frequency and severity of symptoms and signs of CVD, which indicates their comorbidity

Rating of amplitudes of high harmonics in determining feeder with single-phase ground fault

The aim of the paper is theoretical and experimental research of processes during the single-phase ground faults in electrical distribution grids of 10/06/35 kV with isolated neutral mode. The mathematical method of rationing is used for the analysis of the spectral composition of currents and voltages increasing the information content of the allocated higher harmonics of current and voltage. The paper show a comparison of the results of spectral analysis with and without taking into account the mathematical rationing obtained on the simulation model. Field experiments have demonstrated the effectiveness of using of the method of mathematical rationing of the higher harmonic components of current and voltage for various types of single-phase ground faults. The results of field experiments provided an opportunity of improving the methodology of yearling detection of single-phase ground faults in electric grids of 6-10-35 kV with an isolated mode of neutral. The conclusion of the research is the possibility of a significantly more accurate selection of the resonant frequencies of the spectrum of currents and voltages obtained by using of the method of mathematical rationing. The possibility of earlier and more precise localization of the feeder with ground fault is shown on the base more precise selection of the resonant frequency currents and voltages