Long-Term Multiwavelength Studies of High-Redshift Blazar 0836+710

Aims. The observation of gamma -ray flares from blazar 0836+710 in 2011, following a period of quiescence, offered an opportunity to study correlated activity at different wavelengths for a high-redshift (z=2.218) active galactic nucleus. Methods. Optical and radio monitoring, plus Fermi-LAT gamma-ray monitoring provided 2008-2012 coverage, while Swift offered auxiliary optical, ultraviolet, and X-ray information. Other contemporaneous observations were used to construct a broad-band spectral energy distribution. Results. There is evidence of correlation but not a measurable lag between the optical and gamma-ray flaring emission. On the contrary, there is no clear correlation between radio and gamma-ray activity, indicating radio emission regions that are unrelated to the parts of the jet that produce the gamma-rays. The gamma-ray energy spectrum is unusual in showing a change of shape from a power law to a curved spectrum when going from the quiescent state to the active state.Comment: 11 pages, 10 figures, Accepted for publication in A&

Electric field formulation for thin film magnetization problems

We derive a variational formulation for thin film magnetization problems in type-II superconductors written in terms of two variables, the electric field and the magnetization function. A numerical method, based on this formulation, makes it possible to accurately compute all variables of interest, including the electric field, for any value of the power in the power law current-voltage relation characterizing the superconducting material. For high power values we obtain a good approximation to the critical state model solution. Numerical simulation results are presented for simply and multiply connected films, and also for an inhomogeneous film.Comment: 15 p., submitte

Stimulated wave of polarization in spin chains

Stimulated wave of polarization, triggered by a flip of a single spin, presents a simple model of quantum amplification. Previously, it has been found that such wave can be excited in a 1D Ising chain with nearest-neighbor interactions, irradiated by a weak resonant transverse field. Here we explore models with more realistic Hamiltonians, in particular, with natural dipole-dipole interactions. Results of simulations for 1D spin chains and rings with up to nine spins are presented.Comment: 15 pages, 5 figure

RadioAstron space VLBI imaging of polarized radio emission in the high-redshift quasar 0642+449 at 1.6 GHz

Polarization of radio emission in extragalactic jets at a sub-milliarcsecond angular resolution holds important clues for understanding the structure of the magnetic field in the inner regions of the jets and in close vicinity of the supermassive black holes in the centers of active galaxies. Space VLBI observations provide a unique tool for polarimetric imaging at a sub-milliarcsecond angular resolution and studying the properties of magnetic field in active galactic nuclei on scales of less than 10^4 gravitational radii. A space VLBI observation of high-redshift quasar TXS 0642+449 (OH 471), made at a wavelength of 18 cm (frequency of 1.6 GHz) as part of the Early Science Programme (ESP) of the RadioAstron} mission, is used here to test the polarimetric performance of the orbiting Space Radio Telescope (SRT) employed by the mission, to establish a methodology for making full Stokes polarimetry with space VLBI at 1.6 GHz, and to study the polarized emission in the target object on sub-milliarcsecond scales. Polarization leakage of the SRT at 18 cm is found to be within 9 percents in amplitude, demonstrating the feasibility of high fidelity polarization imaging with RadioAstron at this wavelength. A polarimetric image of 0642+449 with a resolution of 0.8 mas (signifying an ~4 times improvement over ground VLBI observations at the same wavelength) is obtained. The image shows a compact core-jet structure with low (~2%) polarization and predominantly transverse magnetic field in the nuclear region. The VLBI data also uncover a complex structure of the nuclear region, with two prominent features possibly corresponding to the jet base and a strong recollimation shock. The maximum brightness temperature at the jet base can be as high as 4*10^13 K.Comment: Accepted for publication in A&A, 10 pages, 6 figure

БЕЗРЕДУКТОРНІ ВІТРОЕНЕРГЕТИЧНІ УСТАНОВКИ

The use of wind farms has great long-term potential as a highly efficient alternative source of cheap energy. The article is devoted to the development of new designs of wind power plants with the participation of the authors, which increase their energy, economic and operational efficiency. The developments concern designs that allow the use of a gearbox to be disconnected to connect a generator included in a wind farm. The principle of operation according to which depending on the magnitude of the voltage of the generator, ie the magnitude of the wind turbine speed, is connected to the thyristor rectifier one of the secondary windings of the transformer by means of switching on the corresponding pair of triacs by the device of selecting the working secondary winding. It is substantiated that any hardware logic or software-logic device, including a generator voltage sensor and threshold elements, will be used as a device for selecting the secondary transformer winding of the transformer, which will activate the corresponding pair of triacs depending on the voltage value of the generator. It is substantiated that the above-mentioned developments can be widely used in the creation of wind turbines with wind turbines of various design and purpose - with a horizontal or vertical axis of rotation, which includes generators for converting the energy of VP into electrical. It has been proved that the creation of an industrial or domestic wind turbine is one of the main tasks of ensuring an acceptable level of economic efficiency, realized by solving a number of technical problems.Применение ветроэнергетических установок имеет большой долгосрочный потенциал как высокоэффективный альтернативный источник дешевой энергии. Статья посвящена выполненным с участием авторов разработкам новых конструкций ветроэнергетических установок, которые повышают их энергетическую, экономическую и эксплуатационную эффективность. Разработки касаются конструкций, которые позволяют отказаться от использования редуктора для присоединения генератора, входящего в состав ветроэнергетической установки. Изложен принцип работы, в соответствии с которым в зависимости от величины напряжения генератора, то есть величины скорости ветротурбины, к тиристорному выпрямителю подключается одна из вторичных обмоток трансформатора при помощи включения соответствующей пары симисторов устройством выбора рабочей вторичной обмотки. Обосновано, что в качестве устройства выбора рабочей вторичной обмотки трансформатора может быть использовано любое аппаратное логическое или программно-логическое устройство, включающее в себя датчик напряжения генератора и пороговые элементы, которые будут производить включение соответствующей пары симисторов в зависимости от величины напряжения генератора. Обосновано, что приведенные  разработки могут найти широкое применение при создании ВЭУ с ветротурбинами различной конструкции и назначения – с горизонтальной или вертикальной осью вращения, в состав которых входят генераторы для преобразования энергии ВП в электрическую. Доказано, что при создании ВЭУ промышленного или бытового назначения одной из основных задач представляется обеспечение приемлемого уровня экономической эффективности, реализуемое путем решения ряда технических задач.Використання вітроенергетичних установок має великий довгостроковий потенціал, як високоефективний альтернативне джерело дешевої енергії. У статті наведено авторські розробки нових конструкцій вітроенергетичних установок, які підвищують їх енергетичну, економічну та експлуатаційну ефективність. Розробки стосуються   конструкцій, які дозволяють відмовитись від використання редукторів для приєднання генераторів, що знаходяться в установці вітроенергетичної установки. Викладено принцип роботи, відповідно до якого в залежності від величини напруги генератора, тобто величини швидкості вітротурбіни, до тиристорного випрямителя підключається одна з вторинних обмоток трансформатора за допомогою включення відповідної пари сімісторів пристроєм вибору робочої вторинної обмотки. Обгрунтовано, що в якості пристрою вибору робочої вторинної обмотки трансформатора може бути використано будь-який апаратний, логічний або програмно-логічний пристрій, що включає в себе датчик напруги генератора і порогові елементи, які будуть виробляти включення відповідної пари сімісторів в залежності від величини напруги генератора. Обґрунтовано, що наведені розробки можуть знайти широке застосування при створенні ВЕУ з вітротурбінами різної конструкції і призначення - з горизонтальною або вертикальною віссю обертання, до складу яких входять генератори для перетворення енергії ВП в електричну. Доведено, що при створенні ВЕУ промислового або побутового призначення однією з основних задач є забезпечення прийнятного рівня економічної ефективності, яке реалізується шляхом вирішення низки технічних завдань

Thermal regimes of HTS cylinders operating in devices for fault current limitation

We reveal obstacles related to the application of HTS cylinders in current limiting devices based on the superconducting - normal state transition. It is shown that, at the critical current density achieved presently in bulk materials, and especially in BSCCO-2212, the required thickness of the cylinder wall in a full-scale inductive device achieves several centimeters. A simple mathematical model of the operation of an inductive fault current limiter (FCL) is used to show that such cylinders cannot be cooled in admissible time after a fault clearing and, hence, the inductive FCLs and current-limiting transformers employing BSCCO cylinders do not return to the normal operation in the time required. For the recovery even with a non-current pause in the circuit, the cylinders are needed with the critical current density by an order higher than the existed ones.Comment: 15 pages, 5 figure

Flaring Activity from 0836+710 (4C +71.07): What Can We Learn With Limited Multiwavelength Coverage?

After a long period of quiescence in \gamma-rays, blazar 0836+710 (4C +71.07) flared in the Spring of 2011. We found only limited multiwavelength coverage of the source. An indication of correlated optical / \gamma-ray variability is not surprising for a Flat Spectrum Radio Quasar (FSRQ) like this one. Radio observations at high frequencies, however, had seen a flare in 2010, well offset from possible \gamma-ray activity. The 2011 \gamma-ray activity comes during a period of rising radio emission, a pattern that has been seen since the EGRET era.Comment: 5 pages,2 figures, proceedings of 'Fermi & Jansky:Our Evolving Understanding of AGN

A novel countermeasure against the reaction time index of countermeasure use in the P300-based complex trial protocol for detection of concealed information

A P300 deception detection protocol was tested using simultaneous versus serial countermeasures and stimulus acknowledgment responses. Previously, P300 showed recognition and elevated reaction time identified countermeasure use. Probe-irrelevant P300 differences were significant in both countermeasure groups and control group. Detection rates were 11/12 for controls, 10/12 for serial countermeasure users, and 11/13 for simultaneous countermeasure users. Reaction time detected countermeasure use in serial responders, but not simultaneous responders. The simultaneous response reaction times were indistinguishable from controls