The Magnificent Seven: Magnetic fields and surface temperature distributions

Presently seven nearby radio-quiet isolated neutron stars discovered in ROSAT data and characterized by thermal X-ray spectra are known. They exhibit very similar properties and despite intensive searches their number remained constant since 2001 which led to their name ``The Magnificent Seven''. Five of the stars exhibit pulsations in their X-ray flux with periods in the range of 3.4 s to 11.4 s. XMM-Newton observations revealed broad absorption lines in the X-ray spectra which are interpreted as cyclotron resonance absorption lines by protons or heavy ions and / or atomic transitions shifted to X-ray energies by strong magnetic fields of the order of 10^13 G. New XMM-Newton observations indicate more complex X-ray spectra with multiple absorption lines. Pulse-phase spectroscopy of the best studied pulsars RX J0720.4-3125 and RBS 1223 reveals variations in derived emission temperature and absorption line depth with pulse phase. Moreover, RX J0720.4-3125 shows long-term spectral changes which are interpreted as due to free precession of the neutron star. Modeling of the pulse profiles of RX J0720.4-3125 and RBS 1223 provides information about the surface temperature distribution of the neutron stars indicating hot polar caps which have different temperatures, different sizes and are probably not located in antipodal positions.Comment: 10 pages, 8 figures, to appear in Astrophysics and Space Science, in the proceedings of "Isolated Neutron Stars: from the Interior to the Surface", edited by D. Page, R. Turolla and S. Zan

Improving the theory for calculating the rational modes of traction electrical equipment

Research shows that the existing theory and methods for calculating rational operating modes of traction electrical equipment do not provide a sufficient level of adequacy under real operating conditions of urban electric transport, which is due to the high complexity of the processes and the lack of a sufficiently developed methodology for their interpretation in industry theory. The purpose of the study was researching the process of electric traction as a result of transformation electrical energy in purposeful mechanical movement of electric rolling stock with the implementation of all technological conditions of production and technical system of urban electric transport. The scientific hypothesis that the modes of operation of electric traction equipment as part of an automated electric drive of the rolling stock of urban electric transport are formed under the influence of a complexly organized technological process of electric traction and are the topological basis of its structure is theoretically substantiated. The main result of the research is the formulated theoretical system which allows us to present the process of electric traction as a system consisting of five levels that are in hierarchical relations and solve each specific problem of building the movement of electric transport. Such an approach will contribute to the development of theory and methods for calculating rational operating modes of traction electrical equipment of urban electric transport, the improvement of the energy efficiency of which is the actual scientific problem

Radioelectronic wireless systems for non-invasive diagnostics of tubular bone fractures during body osteosynthesis

Резюме. Під час реабілітації хворого випадкові та ударні навантаження є основною причиною асептичного розхитування та пошкодження елементів фіксуючої конструкції (ФК). Відсутність контролю утворення хрящової мозолі в зоні перелому викликає збільшення періоду непрацездатності та підвищенню матеріальних затрат, пов'язаних із перебуванням хворого на лікарняному. Змодельовано часткове навантаження на кістку, яке становить 25% від розрахункового значення, та яке дорівнює середній вазі тіла пацієнта. На підставі отриманих даних розроблено новий спосіб та пристрій неінвазивного виявлення початкового моменту послаблення або зламу фіксуючої конструкції, виявлення неправильного зрощення перелому, діагностики утворення та контролю росту хрящової мозолі, виявлення появи початкового моменту запального процесу в тілі хворого і діагностування причин виникнення цього процесу. Сформульовано вимоги до можливого методу неінвазивної діагностики стану перелому трубчастої кістки. Встановлено критеріальні залежності контрольованих параметрів. Доведено дію випадкових навантажень, які є причиною поломок фіксуючої конструкції. Безпровідна передача електроенергії та інформації дозволили розробити метод неінвазивного контролю та діагностики перелому трубчастих кісток та встановити критеріальні залежності між контрольованими параметрами. Для комплексної діагностики стану одужання хворого достатньо контролювати тиск у трьох точках, згинаючий момент у місці перелому кістки, температуру накісткової пластини і температуру будь-якої іншої точки тіла. Resume. During the rehabilitation of the patient, accidental and shock loads are the main cause of aseptic loosening and damage to the elements of the fixing structure (FC). The lack of control over the formation of cartilaginous callus in the fracture zone causes an increase in the period of incapacity for work and an increase in material costs associated with the patient's stay in the hospital. The partial load on the bone is simulated, which is 25% of the calculated value and is equal to the average body weight of the patient. On the basis of the obtained data, a new method and device were developed for non-invasive detection of the initial moment of weakening or fracture of the fixing structure, detection of improper fracture fusion, diagnosis of the formation and control of cartilage callus growth, detection of the appearance of the initial moment of the inflammatory process in the patient's body and diagnosis of the causes of this process. The requirements for a possible method of non-invasive diagnosis of the condition of a tubular bone fracture are formulated. Criterion dependencies of the controlled parameters were established. The effect of random loads, which are the cause of failures of the fixing structure, has been proven. Wireless transmission of electricity and information made it possible to develop a method of non-invasive control and diagnosis of fracture of tubular bones and to establish criterion dependencies between controlled parameters. For a comprehensive diagnosis of the patient's recovery, it is sufficient to monitor the pressure at three points, the bending moment at the site of the bone fracture, the temperature of the periosteum and the temperature of any other point of the body

Introduction of isothiuronium surfactant series: Synthesis, structure-dependent aggregation overview and biological activity

© 2020 Elsevier B.V. For a homologous series of isothiuronium surfactants (S-alkylisothiuronium bromides, CnSU, where n = 10, 12, 14, 16, 18), a synthesis procedure is described and aggregation properties are comprehensively characterized by a variety of techniques. Krafft temperature and critical micelle concentration (cmc) are obtained by methods of conductometry, tensiometry, spectrophotometry, fluorimetry. Using dynamic light scattering and NMR diffusometry, aggregate sizes in aqueous solutions were determined. The aggregation numbers of CnSU systems were estimated by alternative methods. An increase in the length of the alkyl tail from 10 to 16 carbon atoms leads to a decrease in cmc from 16 to 0.5 mM with a decrease in aggregation numbers. S-alkylisothiuronium bromides exhibit solubilization capacity toward a hydrophobic dye Orange OT which is 2–3 times higher than that of alkyltrimethylammonium analogues. Improved solubilization characteristics along with antimicrobial properties manifested at the concentrations of low hemolytic activity allow us to recommend these amphiphiles for the fabrication of soft nanocontainers for hydrophobic guests showing their own biological functionality