Magnetosensitive e-skins with directional perception for augmented reality

Electronic skins equipped with artificial receptors are able to extend our perception beyond the modalities that have naturally evolved. These synthetic receptors offer complimentary information on our surroundings and endow us with novel means of manipulating physical or even virtual objects. We realize highly compliant magnetosensitive skins with directional perception that enable magnetic cognition, body position tracking, and touchless object manipulation. Transfer printing of eight high-performance spin valve sensors arranged into two Wheatstone bridges onto 1.7-mm-thick polyimide foils ensures mechanical imperceptibility. This resembles a new class of interactive devices extracting information from the surroundings through magnetic tags. We demonstrate this concept in augmented reality systems with virtual knob-turning functions and the operation of virtual dialing pads, based on the interaction with magnetic fields. This technology will enable a cornucopia of applications from navigation, motion tracking in robotics, regenerative medicine, and sports and gaming to interaction in supplemented reality

Tailoring electron beams with high-frequency self-assembled magnetic charged particle micro optics

Tunable electromagnets and corresponding devices, such as magnetic lenses or stigmators, are the backbone of high-energy charged particle optical instruments, such as electron microscopes, because they provide higher optical power, stability, and lower aberrations compared to their electric counterparts. However, electromagnets are typically macroscopic (super-)conducting coils, which cannot generate swiftly changing magnetic fields, require active cooling, and are structurally bulky, making them unsuitable for fast beam manipulation, multibeam instruments, and miniaturized applications. Here, we present an on-chip microsized magnetic charged particle optics realized via a self-assembling micro-origami process. These micro-electromagnets can generate alternating magnetic fields of about ±100 mT up to a hundred MHz, supplying sufficiently large optical power for a large number of charged particle optics applications. That particular includes fast spatiotemporal electron beam modulation such as electron beam deflection, focusing, and wave front shaping as required for stroboscopic imaging

Self-assembly as a tool to study microscale curvature and strain-dependent magnetic properties

The extension of 2D ferromagnetic structures into 3D curved geometry enables to tune its magnetic properties such as uniaxial magnetic anisotropy. Tuning the anisotropy with strain and curvature has become a promising ingredient in modern electronics, such as flexible and stretchable magnetoelectronic devices, impedance-based field sensors, and strain gauges, however, has been limited to extended thin films and to only moderate bending. By applying a self-assembly rolling technique using a polymeric platform, we provide a template that allows homogeneous and controlled bending of a functional layer adhered to it, irrespective of its shape and size. This is an intriguing possibility to tailor the sign and magnitude of the surface strain of integrated, micron-sized devices. In this article, the impact of strain and curvature on the magnetic ground state and anisotropy is quantified for thin-film Permalloy micro-scale structures, fabricated on the surface of the tubular architectures, using solely electrical measurements

Direct imaging of nanoscale field-driven domain wall oscillations in Landau structures

Linear oscillatory motion of domain walls (DWs) in the kHz and MHz regime is crucial when realizing precise magnetic field sensors such as giant magnetoimpedance devices. Numerous magnetically active defects lead to pinning of the DWs during their motion, affecting the overall behavior. Thus, the direct monitoring of the domain wall's oscillatory behavior is an important step to comprehend the underlying micromagnetic processes and to improve the magnetoresistive performance of these devices. Here, we report an imaging approach to investigate such DW dynamics with nanoscale spatial resolution employing conventional table-top microscopy techniques. Time-averaged magnetic force microscopy and Kerr imaging methods are applied to quantify the DW oscillations in Ni81Fe19 rectangular structures with Landau domain configuration and are complemented by numeric micromagnetic simulations. We study the oscillation amplitude as a function of external magnetic field strength, frequency, magnetic structure size, thickness and anisotropy and understand the excited DW behavior as a forced damped harmonic oscillator with restoring force being influenced by the geometry, thickness, and anisotropy of the Ni81Fe19 structure. This approach offers new possibilities for the analysis of DW motion at elevated frequencies and at a spatial resolution of well below 100 nm in various branches of nanomagnetism

Численно - аналитический подход к определению производных устойчивости и управляемости в продольном канале беспилотного летательного аппарата нормальной схемы при малых дозвуковых скоростях полета

Розглянуті питання визначення похідних стійкості та керованості безпілотного літального апарату нормальної схеми з малою дозвуковою швидкістю польоту у поздовжньому каналі. Запропоновано чисельно-аналітичний підхід до визначення похідних стійкості та керованості на основі аналізу результатів продувок моделей в аеродинамічній трубі та проведених аналітичних досліджень. Отримані результати дають можливість аналізувати рух БПЛА у поздовжньому каналі, визначати коефіцієнти математичної моделі БПЛА, визначати характеристики стійкості та керованості БПЛА при проектуванні систем автоматичного керування.The problems of determining the stability and control derivatives of small subsonic UAV in the longitudinal channel are solved. An approach to the stability and control derivatives determination based on the analysis results of wind tunnel investigation and analyzes conducted. To the longitudinal movement usually referred traffic aircraft where it is in the plane of symmetry of one and the same vertical plane. Thus the aerodynamic lateral force, rolling moment and yaw angles of heel and slip and angular velocity of roll and glide zero. To investigate the longitudinal motion of the aircraft (movement in the longitudinal channel) important issue is to determine the components of the aerodynamic forces and moments as a function of the kinematic parameters of the flight, the so-called aerodynamic derivatives. Given that the object is a lightweight UAV that has subsonic range of operating speeds, significantly less than the speed of sound, it should be noted that the derivative of the coefficient of lift coefficient and drag coefficient for longitudinal moment of flight speed can be taken to be zero at subsonic speed range. This is due to the fact that these values are almost constant with airspeed, lower the speed of sound. Change the value of these parameters with growth rate appears only when approaching the speed of sound, due to changes in the position of the center of pressure and the additional impedance. Also, when calculating stability derivatives are generally neglected by changing the drag because the drag value of derivatives are small and commensurate with the error of the calculation methods. Derivatives of lift coefficient by the following kinematic parameters: angle of attack, the angular velocity of rotation around the transverse axis, rate of change of angle of attack and angle of elevator deflection are defined. Obtained results make it possible to analyze the movement of the UAV in the longitudinal channel and determinate the coefficients of a mathematical model of the UAV. Also possible to determinate the stability and controllability of the UAV during automatic control systems design.Рассмотрены вопросы определения производных устойчивости и управляемости беспилотного летательного аппарата нормальной схемы с малой дозвуковой скоростью полета в продольном канале. Предложен численно-аналитический подход к определению производных устойчивости и управляемости на основе анализа результатов продувок моделей в аэродинамической трубе и проведенных аналитических исследований. Полученные результаты дают возможность анализировать движение БПЛА в продольном канале, определять коэффициенты математической модели БПЛА, определять характеристики устойчивости и управляемости БПЛА при проектировании систем автоматического управления

Идентификация аэродинамических коэффициентов математической модели бокового движения летательного аппарата

Системи автоматичного керування літальним апаратом повинні забезпечувати точну і швидку реакцію на командний вплив, незважаючи на значні зміни умов польоту. Адаптивне керування є одним з основних методів вирішення таких проблем як точне і швидке визначення поточних параметрів під час польоту. У даній статті запропонований метод, який є вдосконаленим методом ідентифікації на основі синтезу адаптивної системи. Він поєднує переваги відомих методів ідентифікації аеродинамічних коефіцієнтів поданих у відкритих джерелах. Метод ідентифікації аеродинамічних коефіцієнтів дозволяє досить добре визначати аеродинамічні коефіцієнти із записів льотних випробувань: після проведення ідентифікації збільшується ступінь збіжності перехідних процесів реального ЛА і його математичної моделі. Цей метод забезпечить підвищення точності ідентифікації параметрів руху ЛА.The aim of this work is to develop improved methods of identifying the aerodynamic coefficients based on the synthesis of adaptive system, an adaptive algorithm aiming to identify and study the relations to identify and refine the aerodynamic parameters not maneuver lateral motion of the aircraft. The method combines the advantages of the known methods for the identification of the aerodynamic coefficients, which are presented in the public domain. The main problem lies in the fact that by traditional flight test aerodynamic coefficients are a set of discrete values. Linear model, which then is used does not describe accurately coefficients in flight, especially when changing parameters in a wide range of flight. The basic idea of the method consists in the following: synthesizing adaptive system that eliminates the inconsistency between the calculated values of the phase coordinates by which to identify and value, taken from the record flight tests. Simulation of changes in time of the phase coordinates is based on the results of other flight tests phase coordinates and mathematical model aircraft. After processing the records modified aircraft movement on the proposed algorithm we obtain the value of aerodynamic coefficients as a function of time for small changes in the parameters of flight and as a function of angle, angular velocity and deviation of steering for changing flight parameters in large range. The method of identification of the aerodynamic coefficients can fairly well determine the aerodynamic coefficients from flight test records: after identification increases the degree of real convergence of transient aircraft and its mathematical model. This method will improve the accuracy of identification of the aircraft motion parameters and therefore improve the quality of control.Системы автоматического управления летательным аппаратом должны обеспечивать точную и быструю реакцию на командное влияние, несмотря на значительные изменения условий полета. Адаптивное управление является одним из основных методов решения таких проблем как точное и быстрое определение текущих параметров вовремя полета. В данной статье предложен метод, который является усовершенствованным методом идентификации на основе синтеза адаптивной системы. Он сочетает преимущества известных методов идентификации аэродинамических коэффициентов, которые представлены в открытых источниках. Метод идентификации аэродинамических коэффициентов позволяет достаточно хорошо определять аэродинамические коэффициенты из записей летных испытаний: после проведения идентификации увеличивается степень сходимости переходных процессов реального ЛА и его математической модели. Этот метод обеспечит повышение точности идентификации параметров движения ЛА

Green tea, red wine and lemon extracts reduce experimental tumor growth and cancer drug toxicity

Aim: To evaluate antitumor effect of plant polyphenol extracts from green tea, red wine lees and/or lemon peel alone and in combination with antitumor drugs on the growth of different transplanted tumors in experimental animals. Materials and Methods: Green tea extract (GTE) was prepared from green tea infusion. GTE-based composites of red wine (GTRW), lemon peel (GTRWL) and/or NanoGTE as well as corresponding nanocomposites were prepared. The total polyphenolics of the different GTE-based extracts ranged from 18.0% to 21.3%. The effects of GTE-based extracts were studied in sarcoma 180, Ehrlich carcinoma, B16 melanoma, Ca755 mammary carcinoma, P388 leukemia, L1210 leukemia, and Guerin carcinoma (original, cisplatin-resistant and doxorubicin-resistant variants). The extracts were administered as 0.1% solution in drinking water (0.6–1.0 mg by total polyphenolics per mouse per day and 4.0–6.3 mg per rat per day). Results: Tumor growth inhibition (TGI) in mice treated with NanoGTE, cisplatin or cisplatin + NanoGTE was 27%, 55% and 78%, respectively, in Sarcoma 180%, 21%, 45% and 59%, respectively, in Ehrlich carcinoma; and 8%, 13% and 38%, respectively in B16 melanoma. Composites of NanoGTE, red wine, and lemon peel (NanoGTRWL) enhanced the antitumor effects of cyclophosphamide in mice with Ca755 mammary carcinoma. The treatment with combination of NanoGTE and inhibitors of polyamines (PA) synthesis (DFMO + MGBG) resulted in significant TGI of P388 leukemia (up to 71%) and L1210 leukemia. In rats transplanted with Guerin carcinoma (parental strain), treatment with GTRW or GTE alone resulted in 25–28% TGI vs. 55–68% TGI in cisplatin-treated animals. The inhibition observed in the case of combination of GTE or GTRW with cisplatin was additive giving 81–88% TGI. Similar effects were observed when combinations of the cytostatics with GTE (or ­NanoGTE) were tested against cisplatin- or doxorubicin-resistant Guerin carcinoma. Moreover, the plant extracts lowered side toxicity of the drugs. Treatment with GTE, NanoGTE, and NanoGTRW decreased the levels of malondialdehyde in heart, kidney and liver tissue of experimental animals, as well as the levels of urea and creatinine in blood serum, increased erythrocyte and platelet counts, hemoglobin content, and decreased leucocyte counts. Conclusion: The obtained data indicate the prospects for further deve­lopment of GTE and corresponding nanocomposites as auxiliary agents in cancer chemotherapy. Key Words: polyphenolic plant extracts, antitumor effect, cancer therapy

New trends in the economic systems management in the context of modern global challenges

New trends in the economic systems management in the context of modern global challenges: collective monograph / scientific edited by M. Bezpartochnyi, in 2 Vol. // VUZF University of Finance, Business and Entrepreneurship. – Sofia: VUZF Publishing House “St. Grigorii Bogoslov”, 2020. – Vol. 1. – 309 p

Система расселения энтомологического препарата для малого беспилотного летательного аппарата

Спроектовано систему розселення ентомологічного препарату «трихограма», що дозволяє забезпечити витрату активної речовини 1-2 г/га. Рівномірність внесення складає 85%. Розроблено варіант компонування системи на безпілотному літальному апараті «А-1». Проведено математичне та комп’ютерне моделювання системи. Розроблено методику розрахунку потрібної швидкості польоту та кута розпилення в залежності від потрібної ширини зони розпилення та масової витрати активної речовини.Separation systems for entomological substance «trychogramm» were designed. This system provides substance discharge of 1-2 gram/hectare. Uniformity of dispersion comes to 85%. Variant of mounting system on the UAV «A-1» were developed. Mathematical and computer simulation were provided. Method for calculating required airspeed and angle of dispersion depending to dispersion zone width and weight rate created.Спроектирована система расселения энтомологического препарата «трихограмма», которая позволяет обеспечить расход активного вещества 1-2 г/га. Равномерность расселения составляет 85%. Разработан вариант компоновки системы на беспилотном летательном аппарате «А-1». Проведено математическое и компьютерное моделирование системы. Разработана методика расчета потребной скорости полета и угла распыления в зависимости от потребной ширины зоны распыления и массового расхода активного вещества