High-Quality Fast QPOs from Magnetars: An Electric Circuit Model

2011 ◽  
Vol 20 (2) ◽  
Author(s):  
Alexander Stepanov ◽  
Valery Zaitsev ◽  
Esko Valtaoja

AbstractAn interpretation of high-frequency (20-2400 Hz) fast quasiperiodic oscillations of magnetars in terms of an equivalent electric circuit is given. Observed periods and the very high quality of quasi-periodic oscillations are explained. The oscillation source is represented as a hot electron-positron plasma in a ‘trapped fireball’, a system of current-carrying magnetic loops of various sizes. The physical parameters of a ‘trapped fireball’ in the flare of SGR 1806-20 (2004 December 27) are estimated.

2021 ◽  
Vol 9 (2) ◽  
pp. 229
Author(s):  
Georgy Mitrofanov ◽  
Nikita Goreyavchev ◽  
Roman Kushnarev

The emerging tasks of determining the features of bottom sediments, including the evolution of the seabed, require a significant improvement in the quality of data and methods for their processing. Marine seismic data has traditionally been perceived to be of high quality compared to land data. However, high quality is always a relative characteristic and is determined by the problem being solved. In a detailed study of complex processes, the interaction of waves with bottom sediments, as well as the processes of seabed evolution over short time intervals (not millions of years), we need very high accuracy of observations. If we also need significant volumes of research covering large areas, then a significant revision of questions about the quality of observations and methods of processing is required to improve the quality of data. The article provides an example of data obtained during high-precision marine surveys and containing a wide frequency range from hundreds of hertz to kilohertz. It is shown that these data, visually having a very high quality, have variations in wavelets at all analyzed frequencies. The corresponding variations reach tens of percent. The use of the method of factor decomposition in the spectral domain made it possible to significantly improve the quality of the data, reducing the variability of wavelets by several times.


Utilitas ◽  
2002 ◽  
Vol 14 (3) ◽  
pp. 339-359 ◽  
Author(s):  
Torbjorn Tannsjo

Derek Parfit has famously pointed out that ‘total’ utilitarian views, such as classical hedonistic utilitarianism, lead to the conclusion that, to each population of quite happy persons there corresponds a more extensive population with people living lives just worth living, which is (on the whole) better. In particular, for any possible population of at least ten billion people, all with a very high quality of life, there must be some much larger imaginable population whose existence, if other things are equal, would be better, even though its members have lives that are barely worth living. This world is better if the sum total of well-being is great enough, and it is great enough if only enough sentient beings inhabit it. This conclusion has been considered by Parfit and others to be ‘repugnant’.


Solar Energy ◽  
2003 ◽  
Author(s):  
Tetsuo Munakata ◽  
Satoshi Someya

Conversion efficiency of solar cell is strongly affected by quality of substrate and the quality of substrate is influenced by melt convection if the substrate crystal is grown by melt growth technique. Therefore, melt convection control techniques are important to produce a high quality single crystal. In this paper, we have proposed a high frequency magnetic field applied CZ method and investigated the effect of high frequency magnetic field on silicon melt convection. The result reveals that the high frequency magnetic fields affect the tendency of the melt convection: until certain intensity of the high frequency magnetic field, the melt convection is suppressed and above such intensity of the high frequency magnetic field, the melt convection intensity is enhanced. This result indicates that the melt convection can be controlled by the high frequency magnetic field and the high quality silicon single crystals will be grown by this method.


2014 ◽  
Vol 1044-1045 ◽  
pp. 1549-1552 ◽  
Author(s):  
Otakar Cigler ◽  
Karel Kubečka ◽  
Petr Waldstein

The construction and rehabilitation of buildings and structures are intervention in the environment of people. Therefore, we are always looking for new technologies that are not only environmentally friendly but also acceptable from the point of view. Speed, flexibility, minimum limit for residents and transport, and also a high efficiency is the reason why more and more in recent years carried out the rehabilitation of sewerage using remediation sleeves. One of the systems of trenchless rehabilitation of sewerage systems used in Western Europe is a system company RELINEEUROPE Alphaliner Liner GmBH & co., the company's Technicians have developed one of the most important practices in the area of trenchless rehabilitation of sewerage systems. A large proportion of the development also has operators and owners of the pipeline. Technology offers very high quality of carried out restorations. This article describes the procedures for ensuring the quality of the used in Germany, which is a world leader in the development, production and use of this technology.


1994 ◽  
Vol 336 ◽  
Author(s):  
G. Crovini ◽  
F. Demichelis ◽  
C.F. Pirri ◽  
E. Tresso ◽  
J. Meier ◽  
...  

ABSTRACTThe Very High Frequency (70 MHz) PECVD has recently proven its ability to produce Amorphous silicon with high deposition rates (10 Å/s) without affecting the quality of the Material. A comparative study of the optoelectronic properties of undoped silicon carbon alloys produced by Very High Frequency and by conventional RF (13.56 MHz) is carried out. Conductivity, infrared absorption, optical transmission and deep defect densities via PDS and ESR have been Measured. Deposition parameters under study aie methane fraction and hydrogen dilution. In contrast to conventional PECVD, we observe for VHF depositions an increase of the deposition rate with the addition of Methane. Larger energy gap and smaller Urbach energy values seem to indicate a better incorporation of carbon in the VHF case. A study of the degradation induced by light is also presented.


2021 ◽  
Author(s):  
Igino Coco ◽  
Giuseppe Consolini ◽  
Paola De Michelis ◽  
Fabio Giannattasio ◽  
Michael Pezzopane ◽  
...  

<p>After more than seven years in orbit, the ESA Swarm satellites have provided an already large statistics of measurements of several important physical parameters of the ionosphere. In particular, electron density and temperature are measured by pairs of Langmuir Probes, and the quality of such data is now considered good enough for many studies, either science cases or climatological characterisations. Concerning specifically the electron temperature, a rather elusive parameter which is quite difficult to correctly characterize “in situ”, and for which the past literature is not so abundant with respect to other ionospheric physical quantities, the overall distributions observed by Swarm are qualitatively consistent with expectations from theory and past observations. However, a non-negligible amount of high and very high electron temperature values is regularly observed, whose distributions and properties are not trivial. In this study we aim at characterizing such features statistically as a function of latitude, local time, and season.</p>


2015 ◽  
Vol 21 (3) ◽  
pp. 564-569 ◽  
Author(s):  
Bartlomiej S. Witkowski ◽  
Lukasz Wachnicki ◽  
Sylwia Gieraltowska ◽  
Anna Reszka ◽  
Bogdan J. Kowalski ◽  
...  

AbstractWe present results of cathodoluminescence (CL) investigations of high-quality zinc oxide (ZnO) nanorods obtained by an extremely fast hydrothermal method on a silicon substrate. A scanning electron microscopy (SEM) system equipped with CL allows direct comparison of SEM images and CL maps, taken from exactly the same areas of samples. Investigations are performed at a temperature of 5 K. An interlink between sample microstructure and emission properties is investigated. CL confirms a very high quality of ZnO nanorods produced by our method. In addition, the presence of super radiation effects in ZnO nanorod arrays is suggested.


2020 ◽  
Vol 54 (20) ◽  
pp. 2677-2685 ◽  
Author(s):  
Kamil Dydek ◽  
Anna Boczkowska ◽  
Paulina Latko-Durałek ◽  
Małgorzata Wilk ◽  
Karol Padykuła ◽  
...  

The main goal of this work was the increasing electrical conductivity of carbon-epoxy composites due to implementation of thermoplastic nonwoven veils doped with carbon nanotubes into the composite structure. Nonwovens which differ in areal weight were produced by extrusion of fibers and their thermal pressing. Laminates were fabricated using an out-of-autoclave method and nonwovens were incorporated between each layer of carbon-epoxy unidirectional prepreg. The applied conductive nonwovens improved surface and volume electrical conductivity of carbon fibre reinforced polymer in all directions. Microstructure observations proved a very high quality of the fabricated composites. The implementation of nonwovens affected the crack propagation under loading.


2014 ◽  
Vol 70 (a1) ◽  
pp. C607-C607 ◽  
Author(s):  
Severine Freisz ◽  
Juergen Graf ◽  
Matthew Benning ◽  
Vernon Smith

Advances in crystallographic hardware and software are enabling structural biologists to investigate more challenging projects. Recent developments in hardware and software are greatly increasing the capabilities of in-house diffraction systems making it more routine to obtain de novo structural information in the home lab. Single-wavelength anomalous diffraction (SAD) techniques with Cu Ka or Ga Ka radiation are now widely used for structure solution even in cases involving weak anomalous scatterers, like sulfur. We have now introduced the D8 Venture solution for structural biology with the PHOTON 100 detector featuring the first CMOS active pixel sensor for X-ray crystallography. Our new microfocus source, the METALJET delivers beam intensity exceeding those of typical bending-magnet beamlines. The very high intensity, the small beam focus and the lower air scatter produced by Gallium Kα radiation help to greatly reduce the background scatter. This provides greater signal to noise essential to identify weak anomalous signal. Due to the very weak anomalous scattering of S, data multiplicities in the order of 40 are typically necessary to obtain phases by S-SAD. Collecting high-multiplicity data minimizes systematic experimental errors to measure with very high accuracy the minute intensity difference between Friedel Pairs (1.0 – 1.5 %) [1]. This requires software which optimizes the collection strategy, for example with respect to overall data collection time to minimize radiation damage. The combination of a brighter, more stable X-ray source with a high sensitivity low noise detector have greatly improved the quality of data collected in-house. The high quality allows successful SAD measurements far away from the absorption edge. Here we present a low multiplicity sulfur-SAD phasing experiment on a small Thaumatin crystal showing the high quality of the data collected on the D8 VENTURE with the METALJET.


2013 ◽  
Vol 709 ◽  
pp. 36-39 ◽  
Author(s):  
Shu Jie Zhuang ◽  
Bing Teng ◽  
Li Feng Cao ◽  
De Gao Zhong ◽  
Ke Feng ◽  
...  

4-dimethylamino-N-methyl -4-stilbazolium tosylate(DAST) was synthesized by the condensation and ion exchange reaction of 4-methyl-N-methyl pyridinium tosylate, 4-N,N-dimethylamino -benzaldehyde and silver p-toluenesulfonate, the reaction procedure was easy with high efficiency. The purity of the product was further improved by successive abstersion and recrystallization. The powder was investigated by Fourier transform infrared spectrum, nuclear magnetic resonance and elemental analysis. The results showed that the quality of the powder as crystal raw material was very high, the product could meet the requirements for crystal growth, the procedure of washing the product by chloroform was important to achieve the high quality.


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