Development of Self-Trigger Algorithms for Radio Detection of Air-Showers

The detection of extensive air-showers with radio method isa relatively young. But promising branch in experimental astrophysics ofultrahigh energies. This method allows one to carry out observations re-gardless of weather conditions and time of day, and the precision of recon-struction of the properties of primary particles is comparable to the clas-sical methods. The main disadvantage of this method is the complexityof the trigger implementation. Radio signals from extensive air-showershave a duration of few tens nanoseconds and amplitudes comparable tothe surrounding background. Moreover, industrial noise, tele- and radiobroadcasting signals, as well as noise from the electronic equipment ofthe experiment, often interfere with measurements. Most of the setupsfor detecting radio emission from extensive air-showers use an externaltrigger from optical or particle detectors. Despite numerous attemptsto develop autonomous (operating with an internal trigger) cosmic rayradio detectors, there is still no established cost-effective technology forthe sparse radio arrays. In the present work, we give an overview of ourprogress in this direction, particularly, we describe a noise generator andsimulation study using data from the Tunka-Rex Virtual Observatory

Efficiency estimation of self-triggered antenna clusters for air-shower detection

Air-shower radio arrays operate in low signal-to-noise ratio conditions, which complicates the autonomous measurement of air-shower signals without using an external trigger from optical or scintillator detectors. A simple threshold trigger for radio detector can be efficiently applied onlyin radio-quiet conditions, because for other cases this trigger detects a high fraction of noise pulses. In the present work, we study aspects of independent air-shower detection by dense antenna clusters with a complex real-time trigger system. For choosing the optimal procedures for the real-time analysis, we study the dependence between trigger efficiency, count rate, detector hardware and geometry. For this study, we develop a framework for testing various methods of signal detection and noise filtration for arrays with various specifications and the hardware implementation of these methods based on field programmable gate arrays. The framework provides flexible settings for the management of station-level and cluster-level steps of detecting the signal, optimized for the hardware implementation for real-time processing. It includes data-processing tools for the initialconfiguration and tests on pre-recorded data, tools for configuring the trigger architecture andtools for preliminary estimates of the trigger efficiency at given thresholds of cosmic-ray energyand air-shower pulse amplitude. We show examples of the trigger pipeline developed with this framework and discuss the results of tests on simulated data

Reactive trityl derivatives: stabilised carbocation mass-tags for life sciences applications

The rational design of novel triarylmethyl (trityl)-based mass tags (MT) for mass-spectrometric (MS) applications is described. We propose a "pKR+ rule" to correlate the stability of trityl carbocations with their MS performance: trityls with higher pKR+ values ionise and desorb better. Trityl blocks were synthesised that have high pKR+ values and are stable in conditions of MS analysis; these MTs can be ionised by matrix as well as irradiation with a 337 nm nitrogen laser. 13C-Labelled tags were prepared for MS quantitation applications. Moreover, the tags were equipped with a variety of functional groups allowing conjugation with different functionalities within (bio)molecules to enhance the MS characteristics of the latter. The MS behaviour of model polycationic trityl compounds with and without the matrix was studied to reveal that poly-trityl clusters are always singly charged under the (MA)LDI-TOF conditions. Several peptide-trityl conjugates were prepared and comparisons revealed a beneficial effect of trityl tags on the conjugate detection in MS. Trityl compounds containing para-methoxy- and dimethylamine groups, as well as a xanthene fragment, showed considerable enhancement in MS detection of model peptides; thus they are promising tools for proteomic applications. Dimethoxytrityl derivatives allow one to distinguish between Arg- and Lys-containing peptides. Maleimido trityl derivatives are suitable for the efficient derivatisation of thiol-containing peptides in pyridine

Постмиграционные общества: экономика, политика, культура

To understand the depth of transformations in all spheres of society generated by migration, new terminology is needed. The notion of "postmigrant societies" implies that the distinction between local and migrant population loses its relevance in certain social spheres. According to the familiar epistemological framework, societies are presented as consisting of "local population" on the one hand, and "migrant population" on the other. This understanding, however, is becoming obsolete. First, it does not reflect the fact that the phenomenon of spatial mobility is embedded in the social structure. A significant part of the so-called local population is itself included in migration processes. People who are considered to be part of the "autochthonous population" are in fact migrants themselves due to different circumstances (contract work, long-term stay in another country due to studies, involvement in joint business projects, participation in international scientific teams, availability of real estate abroad, etc.). At the same time, those people who are regarded as "migrants" by common sense can be well integrated into the social institutions of their new homeland. Second, the traditional epistemological framework does not reflect contemporary demographic trends. It is unable to capture two points: (a) population rotation within the framework of circular/pendulum migration; (b) qualitative change in the urban population of industrialized countries

The wireless communications systems in subterahertz frequency range

Background. The subterahertz and terahertz frequency ranges are very promising for development of high speed wireless communications systems because of possibility to get the bandwidth about some tens of GHz, which provides the high channel capacity. However fast signal attenuation at its propagation in atmosphere complicate the operation of communications systems in these ranges. Aim. Use of fixed narrow-beam antennas with high antenna power gain allows to provide the direct surface communications distance to some kilometers. The communications distance limitation can be partially removed decreasing the frequency down to 200 GHz and narrowing the channel bandwidth down to some GHz. Methods.The model of transmitter-receiver system (200-220 GHz) based of modern semiconductor devices is described in the manuscript. Results. The possibility of digital signals transmission with speed up to 1 Gbit/s at the distance of 1 km is experimentally shown. Conclusion. According to calculations the output power of transmitter about some hundreds mW is enough for data transmission at the distance up to 1.5 km with antenna power gain of no less than 50 dB

Политическая аккомодация культурных различий в индустриально развитых обществах

The notion of "political accommodation" applied to the theory and practice of managing cultural diversity could enrich the Russian academic dictionary. Liberal democratic states invented specific mechanisms for political accommodation of cultural differences. Thanks to these mechanisms, the part of the population of a democratic state that is not ready to dissolve into the ethnocultural majority is more or less protected. The law not only prohibits forced assimilation, but also contains a number of norms that allow ethnocultural minorities to maintain their distinctiveness by passing it on from generation to generation. However, this is the case in liberal democracies with a long history. In states that emerged as a result of the collapse of two multinational policies - Yugoslavia and the USSR - the situation sometimes looks quite specific. They take more active measures for cultural homogenization than in previous years. As for Russia, in recent years there have been symptomatic changes in the sphere of ethno-cultural policy, which, although with a number of reservations, can be described in terms of "nationalization"