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2021 ◽  
Vol 11 (1) ◽  
Miaomiao Jin ◽  
Yipeng Gao ◽  
Yongfeng Zhang ◽  
Chao Jiang ◽  
Jian Gan

AbstractMaterials performance can be significantly degraded due to bubble generation. In this work, the bubble growth process is elaborated in Cu by atomistic modeling to bridge the gap of experimental observations. Upon continuous He implantation, bubble growth is accommodated first by nucleation of dislocation network from bubble surface, then formation of dissociated prismatic dislocation loop (DPDL), and final DPDL emission in $$\langle 110\rangle$$ ⟨ 110 ⟩ directions. As the DPDL is found capable of collecting He atoms, this process is likely to assist the formation of self-organized bubble superlattice, which has been reported from experiments. Moreover, the pressurized bubble in solid state manifests the shape of an imperfect octahedron, built by Cu $$\{111\}$$ { 111 } surfaces, consistent with experiments. These atomistic details integrating experimental work fill the gap of mechanistic understanding of athermal bubble growth in Cu. Importantly, by associating with nanoindentation testings, DPDL punching by bubble growth arguably applies to various FCC (face-centered cubic) metals such as Au, Ag, Ni, and Al.

2021 ◽  
Vol 10 (2) ◽  
Anatolii Yurkov ◽  

The main tasks of the experimental work were: checking the pedagogical conditions identified on the basis of theoretical analysis of the establishment of readiness of future military psychologists for professional activity in the Armed Forces of Ukraine in the process of professional training; determining the dynamics of the establishment of readiness of future officers-psychologists for military service in the Armed Forces of Ukraine on the basis of developed criteria and indicators; performing statistical verification and confirming the results of experimental work; analyzing the results obtained and drawing conclusions and recommendations based on the results of the conducted pedagogical research.The study was conducted on the basis of the Military Institute of Taras Shevchenko National University of Kyiv, the Military Academy (Odessa) and the Department of military training of the National Aviation University. Three/four-year cadets, attendees on the training of reserve officers, educators and officers were involved in the experimental work. The given analysis of the components of readiness of future officers-psychologists of the Armed Forces of Ukraine for military service, namely: knowledge of theoretical material, motivation, emotional stability, endurance and communicative component have the root-mean-square results at the end of the experiment the analysis shows an increase in indicators by 10% in experimental groups relative to the control with the same indicators at the beginning of the experiment 58.5%. The qualitative indicator in the control group increased by 13.5%, and in the experimental group by 23.5%.

Maria Starovoitova ◽  
Svetlana Vodneva ◽  
Tatyana Klets ◽  
Elena Nikiforova ◽  
Nadezhda Presnyakova

The educational space of a non-linguistic university makes it possible to conduct a purposeful process of forming the ecological worldview and culture of future specialists in the logic of their professional development. According to the authors, the eco-oriented content of teaching a foreign language can make a great contribution to the implementation of this mission due to the great general cultural and educational potential of this discipline. The paper offers a comprehensive theoretical substantiation of the problem under study, reveals the essence, structure and methodology of the ecological worldview formation of engineering students. The authors make an attempt to model the educational process on the basis of interactive pedagogical technologies, the use of which allows students of non-linguistic areas to solve communicative problems on the basis of environmental topics. The totality of data obtained as a result of the experimental work carried out by the authors confirms the effectiveness of students’ ecological worldview formation through the inclusion of environmental-oriented content in the system of language training at the university.

2021 ◽  
Vol 7 (6) ◽  
pp. 432-438
Ch. Akmatova

The subject of this research is the activity of teaching children’s songs on the subject “Literary reading”. The aim is to test the effectiveness of the evidence-based model in schools and present proven options to primary school teachers. Theoretical, empirical and experimental methods were used in research. In the course of the experimental work, it was shown that the views and attitudes of students and teachers to teaching children’s songs in the subject “Literary reading” were carried out by pedagogical research methods and the obtained results. The methods of teaching in Soviet schools are analyzed depending on the type of work. The peculiarity of the results was that the plot and satirical works were not remembered for a long time and in a humorous and satirical form they revealed the character of people in the works. As a result of experimental activity, a model of teaching children’s song in primary school was demonstrated. As a result, in order to increase the effectiveness of the lesson in teaching competence-based songs for children, teachers were asked to focus on the areas of competence-based teaching methods, modern pedagogical technologies and tools in the teaching process.

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3293
Norbert Kazamer ◽  
Roxana Muntean ◽  
Petru Cristian Vălean ◽  
Dragoș Toader Pascal ◽  
Gabriela Mărginean ◽  

The present study investigates the possibility to apply a vacuum furnace thermal post-treatment as an alternative solution for flame sprayed NiCrBSi wear and corrosion-resistant coatings, deposited on a low alloyed structural steel. The controlled atmosphere offers advantages regarding the fusion of the coating, porosity reduction, and degassing. An improvement of the applied heating-cooling cycle was performed through the variation of time and temperature. The best performing samples were selected by comparing their porosity and roughness values. The chosen samples were subsequently characterized regarding their microstructure, microhardness, sliding wear, and corrosion behavior. The experimental work confirms that the use of a vacuum remelting post-process reduces the porosity below 1% and leads to the formation of a larger quantity of hard boron-containing phases, promoting a significant decrease of the wear rate, while maintaining a good corrosion behavior.

2021 ◽  
Marek Orkisz ◽  
Karolina Pazura

Currently aviation focuses mainlly on increasing the economy and ecology of engines. Production of NOx, CO2 and SO adversaly impacts the environment. Parallel goal to minimize SFC to achieve both lower: emission and mission costs. The optimization of components is thus very important. One of the ways of optimizing cycle is doing that based on compressor maps. However it is very expensive to plot one since experimental work needs to be done. The aim of this article is to present a methodology of creating compressor map based on ENGINE ANALOGY. There was used the virtual bench WESTT CS/BV for tests to receive pressure ratio and mass flow of DGEN 380 for three different values of flight speed and altitude, while the rotational speed was changed. The construction similarity of CFM 56-5B and APS 3200 gives the opportunity to plotted compressor maps using the engine analogy without the need for an experiment or using the virtual bench.

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1914
Alejandra Rubio Hernández-Sampelayo ◽  
Rodrigo Navarro ◽  
Ángel Marcos-Fernández

The synthesis of poly(urethane-urea) (PUUs) bearing deactivated diamines within the backbone polymer chain is presented. Several deactivated diamines present interesting properties for several applications in the biomaterial field due to their attractive biocompatibility. Through an activation with Chloro-(trimethyl)silane (Cl-TMS) during the polymerization reaction, the reactivity of these diamines against diisocyanates was triggered, leading to PUUs with high performance. Indeed, through this activation protocol, the obtained molecular weights and mechanical features increased considerably respect to PUUs prepared following the standard conditions. In addition, to demonstrate the feasibility and versatility of this synthetic approach, diisocyanate with different reactivity were also addressed. The experimental work is supported by calculations of the electronic parameters of diisocyanate and diamines, using quantum mechanical methods.

Sharon Black

Abstract While a considerable body of experimental work has been conducted since the beginning of the 1980s to study whether subtitles enhance the acquisition of other languages in adults, research of this type investigating subtitles as a tool for enhancing children’s language learning and literacy has received less attention. This study provides an integrative review of existing studies in this area and finds extensive evidence that subtitled AV content can indeed aid the acquisition of other languages in children and adolescents, and that it can moreover enhance the literacy skills of children learning to read in their L1 or the official language of the country in which they live and receive schooling. Recommendations for future research are also made, and it is highlighted that further research using eye tracking to measure children’s gaze behaviour could shed new light on their attention to and processing of subtitled AV content.

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3119
Mohammed Riyadh Khalaf ◽  
Ali Hussein Ali Al-Ahmed ◽  
Abbas AbdulMajeed Allawi ◽  
Ayman El-Zohairy

To accommodate utilities in buildings, different sizes of openings are provided in the web of reinforced concrete deep beams, which cause reductions in the beam strength and stiffness. This paper aims to investigate experimentally and numerically the effectiveness of using carbon fiber reinforced polymer (CFRP) strips, as a strengthening technique, to externally strengthen reinforced concrete continuous deep beams (RCCDBs) with large openings. The experimental work included testing three RCCDBs under five-point bending. A reference specimen was prepared without openings to explore the reductions in strength and stiffness after providing large openings. Openings were created symmetrically at the center of spans of the other specimens to represent 40% of the overall beam depth. Moreover, finite elements (FE) analysis was validated using the experimental results to conduct a parametric study on RCCDBs strengthened with CFRP strips. The results confirmed reductions in the ultimate load by 21% and 7% for the un-strengthened and strengthened specimens, respectively, due to the large openings. Although the large openings caused reductions in capacities, the CFRP strips limited the deterioration by enhancing the specimen capacity by 17% relative to the un-strengthened one.

N. Uday Kiran ◽  
S. Hanmanthu ◽  
C. Govardhan

In the present work, an experimental investigation was carried out on self-compacting concrete made with various replacement levels of recycled coarse aggregate. The main aim of the experimental work is to know the suitability and effects of recycled aggregates in SCC. Self-Compacting Concrete is a type of concrete which does not need any kind of vibration or compaction. In the present experimental work, the behaviour of concrete made with recycled aggregates is evaluated and compared with the traditional concrete in which the coarse aggregate is replaced with recycled aggregate by 0%, 50%, and 100% respectively. Mechanical properties of the concrete were evaluated in its fresh and hardened conditions.

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