THE PRECULIARITIES OF CONDUCTING OF PSYCHOPHYSIOLOGICAL EXPERTISE OF PERSONALITY

The article focuses on the problem of appointment and psychophysiological examination of personality. Theoretical approaches to stress resistance as a psychological category and one of the components of expert research are analyzed. Stress resistance is considered as a dynamic, integrative property of personality, as a result of interaction with a stressor, which includes the process of self-regulation, cognitive representation, objective characterization of the situation and requirements for personality. It is formed in the process of personality confrontation with stressors that are repeated in different situations and depend on understanding the life situation, adequate judgments in its interpretation, rational assessment and ability to predict their actions, the ability to choose adequate means of coping with stress. The article considers the level of stress resistance of the individual. The main methods of research of the level of stress resistance and determination of professional suitability are analyzed. The sample, stages of the research are characterized and the obtained results of the study of stress resistance in adolescence are analyzed. The necessity of psychological support to increase the level of personality resilience is discussed. In the article notes that the stress resistance of students is determined by the presence of stressors in the student environment, such as exam situations, periods of social adaptation, the need for personal self-determination in future professional activities. A powerful flow of information in the learning process of students increases the load on the cognitive sphere of personality, which leads to functional changes in the emotional, behavioral and personal spheres. High internal stress can cause complex physiological changes in a young person's body, and strong emotional stress leads to stress.

On-chip environmentally assisted cracking in thin freestanding SiO2 films

An on-chip fracture mechanics method is extended to characterize subcritical crack growth in submicron freestanding films. The method relies on a self-actuated concept based on MEMS fabrication principles. The configuration consists of a notched specimen attached to actuator beams involving high internal stress. Upon release, a crack initiates at the notch, propagates, and arrests. Several improvements are worked out to limit the mode III component and to avoid crack kinking. The method is applied to subcritical crack growth in 140-nm-thick SiO2 films under different humidity conditions. The data reduction scheme relates crack growth rate to stress intensity factor. The static fracture toughness value is ~ 0.73 MPa $$\sqrt{\mathrm{m}}$$ m , with standard error of 0.01 MPa $$\sqrt{\mathrm{m}}$$ m and standard deviation of 0.17 MPa $$\sqrt{\mathrm{m}}.$$ m . Subcritical crack growth rates are much smaller than in bulk specimens. A major advantage is that many test samples can be simultaneously monitored while avoiding any external equipment. Graphic Abstract

A study on preparation and mechanism of Ni based ternary alloy

In this paper, the preparation of Ni–Ti–Nb amorphous alloy materials made by mechanical alloying method has been studied. The Ni–Ti–Nb mixed powders obtained by different mechanical alloying times have been analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the Ni–Ti–Nb mixed powders can be mechanically alloyed after milling for 10 hours, and retained with ball milling. Continuously, Ni, Ti and Nb alloy powders diffuse with each other. When the diffusion rate increases to a certain extent, it is too late to form an ordered structure and form a Ni–Ti–Nb amorphous alloy. The stress and displacement curves are obtained by testing the tensile strength at room temperature. The stress changes of the restrained curves are relatively stable when the displacement is 6–18 mm, and the stress changes of the unconstrained curves show a distinct upward trend when the displacement is 6–18 mm, indicating that the strength of the specimens treated with restraint is higher than that of the specimens treated with restraint. This is due to the high internal stress of the material caused by the restraint and the decrease in the tensile strength of the alloy material.

Effect of current density on the deposit stress in gold electroplating

As the key components of grating-based X-ray phase contrast imaging, absorption gratings are essential to be fabricated. In fact, the internal stress is one of the critical issues for the application of the electroplated gold deposit as the absorption metal for absorption gratings. It is common that high internal stress levels can cause the deposit cracking, blistering and peeling away from the substrate material. This study investigates the effect of current density on the internal stress by the bent strip method. The surface morphologies of gold deposits are examined using scanning electron microscopy (SEM) and the crystal structure of the electroplated deposit is analyzed by X-ray diffraction (XRD). The change of current density reverses the internal stress of the deposits from compressive to tensile. The value of deposit stress can be near zero by optimizing the current density.

Mechanical Properties of Magnesium Alloys Produced by the Heated Mold Continuous Casting Process

Investigation of the tensile and fatigue properties of cast magnesium alloys, created by the heated mold continuous casting process (HMC), was conducted. The mechanical properties of the Mg-HMC alloys were overall higher than those for the Mg alloys, made by the conventional gravity casting process (GC), and especially excellent mechanical properties were obtained for the Mg97Y2Zn1-HMC alloy. This was because of the fine-grained structure composed of the α-Mg phases with the interdendritic LPSO phase. Such mechanical properties were similar levels to those for conventional cast aluminum alloy (Al84.7Si10.5Cu2.5Fe1.3Zn1 alloys: ADC12), made by the GC process. Moreover, the tensile properties (σUTS and εf) and fatigue properties of the Mg97Y2Zn1-HMC alloy were about 1.5 times higher than that for the commercial Mg90Al9Zn1-GC alloy (AZ91). The high correlation rate between tensile properties and fatigue strength (endurance limit: σl) was obtained. With newly proposed etching technique, the residual stress in the Mg97Y2Zn1 alloy could be revealed, and it appeared that the high internal stress was severely accumulated in and around the long-period stacking-order phases (LPSO). This was made during the solidification process due to the different shrinkage rate between α-Mg and LPSO. In this etching technique, micro-cracks were observed on the sample surface, and amount of micro-cracks (density) could be a parameter to determine the severity of the internal stress, i.e., a large amount to micro-cracks is caused by the high internal stress.

Study on Internal Stress in Micro-Electroformed Layer

Micro electroforming technology is widely used in fabrication of multilayer or moveable metal micro devices. The fabrication of these devices is usually suffered from high internal stress in micro-electroformed layers which seriously restricts the application and development of micro electroforming technology. Therefore, to control the internal stress is very important for improving the quality and performance of micro-electroformed layer. However, published studies on internal stress in the electroforming layer were mostly based on additive-free solution. According to additive solution, the effect of ultrasonic and current density on compressive stress occurring in the electroforming layer is investigated in this paper. The results indicate that the compressive stress keeps increasing with current density within range from 0.2 to 2 A/dm2. Meanwhile, the compressive stress in ultrasonic solution decreases by 73.4 MPa averagely comparing to that in ultrasonic-free solution, and the compressive stress also keeps decreasing with the ultrasonic power which gets the lowest value at 200W. Moreover, the mechanisms of additive-induced compressive stress and ultrasonic relieving compressive stress are discussed. This research work will complement the ultrasonic-stress reduction theory and may contribute to the development of micro electroforming technology.

A Study on the Hydrogen Evolving Activity of Electroplated Ni-P Coating by Using the Taguchi Method

The optimal catalytic activity of the electrodeposited Ni-P coating with the control of the process parameters was performed in this study by using Taguchi’s method. The controlled process parameters included current density, duty cycle and the concentration of the phosphorous acid in the electrolyte. The correlation among the controlled parameters and the resulted hydrogen evolution reaction (HER) activity was discussed with emphasis on the influence of the P content, internal stress, roughness and grain size of the coating. The optimal HER property was obtained for the electrodeposition of Ni-P coating with a phosphorous acid concentration of 5g/l, current density of 16A/dm2 and duty cycle of 100 %. The resulted Ni-P coating with a better HER property was the one with P content 3at%, an internal stress higher than 10MPa, grain size 10~15nm and surface roughness higher than 100nm. In addition, the cracking of the coating due to high internal stress favored the raise of the HER activity.

Application of Ultrasonic Stress Relief in the Fabrication of SU-8 Micro Structure

SU-8 photoresist has received a lot of attention in the MEMS field because of its excellent lithography properties. However, its high internal stress affects the overall pattern quality of the micro structures. The purpose of this work is to reduce the internal stress in SU-8 micro structure by ultrasonic stress relief technology. The stress relief mechanism of SU-8 micro structure was presented. The effect of ultrasonic stress relief on SU-8 micro structure was studied by experiments. The experimental results show that the internal stress in SU-8 micro structures can be reduced by ultrasonic stress relief technology.