Optimization of GEM-based detector readout electrode structure for SXR imaging of tokamak plasma

The paper presents an optimization of a readout structure of the GEM-based detector designed for X-ray imaging for DTT tokamak in the energy range of 2–15 keV. The readout electrode of approximately 100 cm2 surface is composed of hexagonal pixels connected in a way that allows reducing the actual number of signal pixels (electronics channels). At the same time, based on time coincidence analysis, it makes possible to unambiguously identify the position of the recorded X-ray photon. For the input spectrum, the Detective Quantum Efficiency (DQE) of the detector was calculated using the Geant4 program and the spatial distributions of electron avalanches at the readout electrode were simulated using the Garfield++ program. These were conducted for a given energy range of radiation and a statistical distribution consistent with the shape of the spectrum considering the DQE of the detector. As a result, the size of a single hexagonal pixel was proposed to capture the position of the recorded radiation quanta in an optimal and effective way.

Model for Assessing the Immunity of Channels Using Frequency Manipulation Signals

The issues of noise immunity of control channels of robotic systems using signals with frequency shift keying are considered. The article presents the results of estimating the probability of a bit error depending on the duration of the intervals at which the time coincidence of the structural interference with the signal occurs. Proposals are formulated for the practical use of the results obtained.

The Effect of Visual and Tennis Training on Perceptual-Motor Skill and Learning of Forehand Drive in Table Tennis Players

Introduction: The present study was designed to investigate the effect of visual and skill training on learning forehand drive in table tennis and motor-perceptual abilities (reaction time, coincidence-anticipation timing, eye-hand coordination, and depth perception).Materials and Methods: Forty volunteer female students (Mean±SD age: 21.50±0.78 years) were selected and randomly assigned to one of four groups (each group had 10 participants): visual and tennis training group, visual training group, tennis training group, and control group. Motor perceptual abilities (reaction time, coincidence-anticipation timing, eye-hand coordination, and depth perception) and forehand drive performance were measured before and after the training period, and also after 24 h retention period. After the pretest, including the accuracy of the kicks test for assessment of forehand drive in table tennis and motor-perceptual test, the experimental groups underwent four weeks (three sessions per week) of visual training, table tennis forehand training, or both. The control group followed their normal daily life for the whole study period. Then, they participated in the posttest and 24 h later in the retention test of kick accuracy.Results: The results revealed that visual and table tennis training, visual training, and table tennis training had a significant effect on the reaction time (P=0.001), coincidence-anticipation timing (P=0.001) and eye-hand coordination (error time) (P=0.01). Moreover, visual and tennis training and table tennis training had a significant effect on the acquisition (P=0.001) and retention of forehand drive (P=0.005). Besides, the post hoc LSD (Least Significant Difference) test showed that visual and tennis training had a more significant impact on the learning forehand drive. Visual training and tennis training had a significant effect on eye-hand coordination (number of errors). The three types of training programs were not effective in the depth of perception.Conclusion: Visual training can be used as a supplementary program in the athletes’ training schedule.

Population dynamics and habitat use by Northern Lapwing Vanellus vanellus in agricultural landscape of Dravsko and Ptujsko polje (NE Slovenia)

The Northern Lapwing numbers across Europe are declining owing to its insufficient breeding success. To determine the size, dynamics and habitat use of the lapwing population at Dravsko and Ptujsko polje, a survey was carried out between 2016 and 2018. In 2016, 2017 and 2018, we recorded 148, 130, and 117 pairs, respectively. The population declined during the study and the population trend is uncertain. Approximately 12 to 21% of the national lapwing population was recorded at Dravsko and Ptujsko polje, making them one of the most important breeding areas in Slovenia. The majority of lapwings were found in bare tilled fields and fields with young spring crops that enable unbroken all-round views. Crop data analysis showed a significant preference for maize fields which are mostly bare tillage at the start of the incubation period and therefore act as an ecological trap for lapwings due to the time coincidence of the nesting period and farming operations. For the protection of the lapwing in Slovenia, we recommend a time limit of farming operations or avoiding individual nests while working in the field. Both measures are recommended to be implemented in combination with the provision of suitable foraging habitat for chicks. For greater effectiveness, we propose priority implementation of conser vation measures on traditiona l breeding sites.

Corneal Perforation in a Patient with Chronic Keratouveitis and Gout: Case Report

The ophthalmic manifestations of gout are rare. There are only few published reports and study about it. The majority of patients with ocular gout abnormalities are asymptomatic. The authors discuss the case of a 43-year-old male who presented with central corneal keratolysis with perforation. The patient has an approximately 14-year history of gout attacks and chronic keratouveitis witch started about the same time. Coincidence of keratouveitis in a patient with gout has not been reported and it is unclear if this condition is rare or may only be by chance at the same time with gout.

LOCATION OF THE γ-RAY FLARING EMISSION IN THE PARSEC-SCALE JET OF THE BL LAC OBJECT AO 0235+164

We locate the γ-ray and lower frequency emission in flares of the BL Lac object AO 0235+164 at ≳12 pc in the jet of the source from the central engine. We employ time-dependent multi-spectral-range flux and linear polarization monitoring observations, as well as ultra-high resolution (~0.15 milliarcsecond) imaging of the jet structure at λ = 7 mm . The time coincidence in the end of 2008 of the propagation of the brightest superluminal feature detected in AO 0235+164 (Qs) with an extreme multi-spectral-range (γ-ray to radio) outburst, and an extremely high optical and 7 mm (for Qs) polarization degree provides strong evidence supporting that all these events are related. This is confirmed at high significance by probability arguments and Monte-Carlo simulations. These simulations show the unambiguous correlation of the γ-ray flaring state in the end of 2008 with those in the optical, millimeter, and radio regime, as well as the connection of a prominent X-ray flare in October 2008, and of a series of optical linear polarization peaks, with the set of events in the end of 2008. The observations are interpreted as the propagation of an extended moving perturbation through a re-collimation structure at the end of the jet's acceleration and collimation zone.