Impact of Friction Stir Processing Parameters on Forming the Structure and Properties in AISI 420 Steel Surface Layer

Research has been done into the influence of friction thermomechanical treatment parameters on forming the structure and properties in a surface layer of 20X13 steel. The paper presents a theoretical approach towards controlling the process variables. A hardened layer with a thickness of 1,7 mm was obtained after 20X13 steel had been subjected to the process. The thickness of the layer that had a microhardness of ≥600HV0,05 turned out to be about 0,75mm while the microstructure of the hardened layer was martensitic, martensitic and perlitic with dispersed inclusions of carbides. It was established that the feed has the biggest influence on the thickness of the hardened layer.     Keywords: friction stir processing, rotation speed, tool feed, normal force, microhardness, microstructure

Double volume reflection of a proton beam by a sequence of two bent crystals

The doubling of the angle of beam deflection due to volume reflection of protons by a sequence of two bent silicon crystals was experimentally observed at the 400 GeV proton beam of the CERN SPS. A similar sequence of short bent crystals can be used as an efficient primary collimator for the Large Hadron Collider

Hardiness and personal resources of red zone staff: Psychological analysis [ЖИЗНЕСТОЙКОСТЬ И ПЕРСОНАЛЬНЫЕ РЕСУРСЫ ВРАЧЕЙ «КРАСНЫХ ЗОН» КОВИД-ГОСПИТАЛЕЙ: ПСИХОЛОГИЧЕСКИЙ АНАЛИЗ]

In light of the ongoing COVID-19 pandemic, it is becoming increasingly important to address the problem of resourcefulness in the healthcare personnel of COVID-19 red zones. The aim of this study was to assess hardiness and the state of vital resources in physicians continuously working in red zones and to test a hypothesis that that long-term work in a COVID-19 red zone adversely affects the resourcefulness, reducing resistance to stress. Group 1 (n = 94) consisted of physicians with a history of employment in a COVID-19 red zone between May 2020 and June 2021; group 2 (n = 77) comprised physicians who were not involved in managing COVID-19 patients. The tests showed that hardiness and its components (commitment, control and challenge) were at high levels in group 2 (59.7%; 67.5%; 61.0%; 20.9%, respectively). The index of resourcefulness (RI; 1.24) reflected the prevalence of personal gains over losses in group 1 over the past year. In this group, there were no sex differences in the results. By contrast, hardiness was significantly reduced in 31.9% of the respondents in group 1 (red zone). Working in the red zone had a devastating effect on all hardiness components: the ratio of the percentages of high to low values was 8.5/27.7 for commitment, 9/6/34.0 for control and 10.6/35.1 for challenge. RI was reduced (0.77). The most pronounced loss of resources was observed in female physicians. The study found a significant mutual impact between challenge and the state of personality resources in red zone staff, which may indicate activation of proactive coping strategies and the acceptance of new professional experience. © 2021 Pirogov Russian National Research Medical University. All rights reserved

Hardiness and personal resources of red zone staff: Psychological analysis

In light of the ongoing COVID-19 pandemic, it is becoming increasingly important to address the problem of resourcefulness in the healthcare personnel of COVID-19 red zones. The aim of this study was to assess hardiness and the state of vital resources in physicians continuously working in red zones and to test a hypothesis that that long-term work in a COVID-19 red zone adversely affects the resourcefulness, reducing resistance to stress. Group 1 (n = 94) consisted of physicians with a history of employment in a COVID-19 red zone between May 2020 and June 2021; group 2 (n = 77) comprised physicians who were not involved in managing COVID-19 patients. The tests showed that hardiness and its components (commitment, control and challenge) were at high levels in group 2 (59.7%; 67.5%; 61.0%; 20.9%, respectively). The index of resourcefulness (RI; 1.24) reflected the prevalence of personal gains over losses in group 1 over the past year. In this group, there were no sex differences in the results. By contrast, hardiness was significantly reduced in 31.9% of the respondents in group 1 (red zone). Working in the red zone had a devastating effect on all hardiness components: the ratio of the percentages of high to low values was 8.5/27.7 for commitment, 9/6/34.0 for control and 10.6/35.1 for challenge. RI was reduced (0.77). The most pronounced loss of resources was observed in female physicians. The study found a significant mutual impact between challenge and the state of personality resources in red zone staff, which may indicate activation of proactive coping strategies and the acceptance of new professional experience

Optically Enhanced Position-Locked Power Analysis

Abstract. This paper introduces a re¯nement of the power-analysis at-tack on integrated circuits. By using a laser to illuminate a speci¯c area on the chip surface, the current through an individual transistor can be made visible in the circuit's power trace. The photovoltaic e®ect converts light into a current that °ows through a closed transistor. This way, the contribution of a single transistor to the overall supply current can be modulated by light. Compared to normal power-analysis attacks, the semi-invasive position-locking technique presented here gives attackers not only access to Hamming weights, but to individual bits of processed data. This technique is demonstrated on the SRAM array of a PIC16F84 microcontroller and reveals both which memory locations are being ac-cessed, as well as their contents. Key words: side-channel attacks, power analysis, semi-invasive attacks, optical probing