Phase Competition Research Articles

Phase formation capability and compositional design of β-phase multiple rare-earth principal component disilicates

A key strategy to design environmental barrier coatings focuses on doping multiple rare-earth principal components into β-type rare-earth disilicates (RE2Si2O7) to achieve versatile property optimization. However, controlling the phase formation capability of (nRExi)2Si2O7 remains a crucial challenge, due to the complex polymorphic phase competitions and evolutions led by different RE3+ combination. Herein, by fabricating twenty-one model (REI0.25REII0.25REIII0.25REIV0.25)2Si2O7 compounds, we find that their formation capability can be evaluated by the ability to accommodate configurational randomness of multiple RE3+ cations in β-type lattice while preventing the β-to-γ polymorphic transformation. The phase formation and stabilization are controlled by the average RE3+ radius and the deviations of different RE3+ combinations. Subsequently, based on high-throughput density-functional-theory calculations, we propose that the configurational entropy of mixing is a reliable descriptor to predict the phase formation of β-type (nRExi)2Si2O7. The results may accelerate the design of (nRExi)2Si2O7 materials with tailored compositions and controlled polymorphic phases.

Effect of welding speed on the microstructure and texture development in the individual weld zone of friction stir welded DP780 steel

In this study, microstructural and texture development in the individual weld zone during friction stir welding (FSW) of DP780 steel at similar tool rotation speed (200 rpm) different welding speeds (200 mm/min and 400 mm/min) was investigated. Phase transformations and competition between recovery and recrystallization mechanisms in the distinct weld zones were explored by electron back scattered diffraction (EBSD). More pronounced grain refinement was observed in stir zone (SZ) of sample welded at higher speed (0.62 μm) as compared to lower welding speed (0.51 μm) which is attributed to the enhanced Zener pinning effect at higher welding speeds. Continuous dynamic recrystallization (cDRX) was found to be the dominating recrystallization mechanism in SZ of both welded samples. Orientation distribution function (ODF) based texture investigations of SZ revealed the development of D1 {1¯1¯2}<111> and D2 {112¯}<111> shear components along with the cube {001}<100> texture. The lower texture intensities witnessed in SZ of higher welding speed sample was due to the accelerated recrystallization kinetics at higher welding speeds. The microstructural investigations of thermo-mechanically affected zone (TMAZ) of both welded samples revealed that cDRX was predominant recrystallization mechanism while microshear bands, grain boundary bulging and geometric DRX (gDRX) also assisted the grain refinement. Texture analysis showed the development of D2 {112¯}<111>, J{110}<11¯2> and J¯{1¯1¯0}<1¯12¯> shear components in the TMAZ lower welding speed sample and D1 {1¯1¯2}<111>, D2 {112¯}<111>, J{110}<11¯2> and J¯{1¯1¯0}<1¯12¯> shear components in the TMAZ of higher welding speed sample. Moreover, heat affected zone (HAZ) of both samples showed higher evolution of low angle grain boundaries (LAGBs) indicating that the grains are in the dynamic recovery stage due to lower temperatures and strain.

Природа общей мощности спектра и очень низкочастотных волн кардиоинтервалограммы с позиций адаптации организма человека к двигательной активности (обзор)

It is known that heart rate variability (HRV), evaluated using interval electrocardiography (ECG), reflects the influence of the autonomic nervous system (АNS) and biologically active substances on cardiac activity. For this reason, interval ECG method is widely used in sports, as it reveals the mechanisms of human adaptation to motor activity. This article analyses data on the median values of the total power (TP) of the HRV spectrum and absolute and relative power of very low frequency (VLF) waves on the interval electrocardiogram in athletes recorded in the supine position. We chose these three indicators out of more than 30 others due to their informativeness and due to the debatable issue of the nature of VLF waves. Literature data and unpublished results of our studies allow us to conclude that the values of these indicators in athletes depend on a number of factors, including type of sports (being especially high in sports building aerobic endurance), level of athletic skill (being maximum in elite athletes) as well as volume and intensity of training. In elite skiers, the values of these three indicators tend to change in the course of the training year, increasing in the preparatory phase, staying at a high level or even increasing during the competitive phase, and decreasing in the transition phase, which is determined by the relevant dynamics of the training volume throughout the year. The authors believe that the increase in the values of these three HRV indicators points to the growing influence of the parasympathetic division of ANS and non-neuronal acetylcholine on cardiac activity under heavy training volumes. According to the authors, the values of these three indicators reflect the level of aerobic motor activity (the higher they are, the higher this activity).

Phase Competition and Strong SHG Responses of the Li2MIIMIVSe4 Family: Atom Response Theory Predictions versus Experimental Results

Compounds of diamond-like (DL) structures are one of the important systems in searching for new high-performance infrared nonlinear optical (IR NLO) materials. However, the phase competition of the diverse DL allotropes and the origin of the SHG response at the atom and orbital level for these NLO materials remain an unsolved hot topic. In this work, the atom response theory (ART) combined with the hybrid density functional calculations was applied to explore the NLO properties of the Li2MIIMIVSe4 (MII = Zn, Cd, Hg; MIV = Si, Ge, Sn) family. Twenty-three new promising IR NLO compounds were predicted with a wide range of band gaps (1.79–3.62 eV), high SHG responses (∼0.7 to 2.5 × AGS), moderate birefringences (∼0.04), and possibly high LIDT (laser-induced damage threshold) values. Among them, Li2HgGeSe4 and Li2HgSnSe4 with the Pna21 structure were experimentally confirmed very recently. The phase competition and the order of band gaps of these compounds were explained from the viewpoint of the crystal structure and chemical bonding. Our ART analyses showed that the large NLO coefficients of these selenides arise mainly from the Se-4p orbitals (∼76%) while the anomaly low contribution of Hg is attributed to the tiny d–p covalent interactions. The SHG responses of all structures were rationalized by the deffp vs αsum/(NEg) linear relationship, showing the importance of this relation in designing and synthesizing new NLO materials.

Mental fatigue changes from regular season to play-offs in semiprofessional soccer: A comparison by training days.

The main purpose was to compare by each training the mental load and fatigue reported by semiprofessional soccer players comparing between regular season phase and the play-offs. Fifty-three players (Mage =24.59 years) for two teams participated during the 2020/21 season. Mental load was measured with a Likert questionnaire. Mental fatigue was quantified with a Visual Analogue Scale. Four trainings were recorded each week (Monday=MD+1, Wednesday=MD-4, Thursday=MD-3 and Saturday=MD-1), with a competitive match on Sunday across 10 weeks (five dates of regular season - five dates of play-offs). A Linear Mixed Model was performed with R-studio, using the training days and the competitive phase as independent variables. The influence of time played as co-variable was also checked. Results showed MD+1 as the more mentally fatiguing day in both phases, although MD-4 were the training with higher mental load reported (p=0.001). Comparing phases, mental fatigue was significantly higher during the play-offs (p=0.037). With regard time played, players that did not usually play showed a decrease in mental load during the play-offs. Then, we recommend coaches to use recovery strategies for mental fatigue, avoid mentally fatiguing tasks close to competition and considerer the time played as a factor which may contribute to individual differences in player mental fatigue.

Plasma Volume Variations in Professional Soccer Players: Difference Between Pre- and Competitive Season

Background: Variations in plasma volume and hematological parameters occur before and after training in soccer players. However, there are no reports on changes in hematological parameters resulting from a half-season of training in professional soccer players. Objectives: To investigate the effects of training load on plasma volume variations in elite soccer players. Methods: Twenty soccer players from the 1st French division soccer league (Ligue 1) were included in the study. The training load was evaluated using the rating of perceived exertion (RPE, 10- Borg scale) after each training session and each match. Anthropometrics characteristics, hematocrit (Ht), hemoglobin (Hb) and plasma volume variations (PVV) were assessed at 3 different times: T1: Baseline (before the first week of pre-season), T2: At the end of pre-season (after 8 weeks of training) and T3: At the end of the first competitive period (after 26 weeks of training and at halfway of the competitive season). Results: Values of Ht and lean body mass (LBM) increased during the first competitive period from T1 to T3 (Ht: ∆↑8%, P = 0.037, effect sizes (ES) = 1.0; LBM: ∆↑4%, P = 0.041, ES = 0.83) and from T2 to T3 (LBM: (∆↑2%; P = 0.05; ES = 0.77). Moreover, PVV decreased from T2 to T3 (P = 0.002, ES = 0.5) and from T1 to T3 (P &lt; 0.05; ES = 1.26). There were no differences in Hb at T1, T2 or T3. Conclusions: Changes in body weights, PVV and Ht during preparatory and competitive phases were affected by the training load and competitive play.

Match performance of football teams in different competition phases: Analysis on the data of eight consecutive seasons in the Chinese Super League.

The study aims to quantify the variation in the physical and technical match performance of football teams in different months of a season in the Chinese Super League (CSL). Data of 1,899 matches in the seasons 2012-2019 of CSL collected by Amisco Pro® were analysed. The generalised mixed modelling was employed to estimate the per match mean values of six physical performance-related parameters and 16 technical performance-related parameters of CSL teams in every month of all the eight seasons. Results showed that: (1) the mean values of all the analysed physical performance-related parameters (total/sprint/HSR/MSR distance, sprint/HSR efforts) of CSL teams through a season were characterised like a 'U' shape, the highest value was observed in the beginning of season (March), then decreased gradually, reaching the lowest in August, and rebounded progressively from September to November; (2) the mean values of eight technical performance-related parameters (goals, shots, shot accuracy, individual possession, individual possession in the last third, crosses, cross accuracy and yellow cards) presented trivial changes through the whole season; (3) the number of passes, passes per shot, forward passes, and time in individual possession showed trivial changes from March to October, but showed a substantially increase in November (the last month of season); (4) Pass accuracy, forward pass accuracy, and the number of mean ball touches per individual possession substantially increased in June, July and August, whilst the number of challenges, ground challenges, air challenges, tackles and fouls all substantially decreased in these 3 months. These results could provide detailed information to help the practitioners choose the best training and match preparation strategy in the means of periodisation in different season phases.

Physical demands during 3 × 3 international male and female basketball games are partially impacted by competition phase but not game outcome.

Despite the increased popularity and number of international competitions for 3 × 3 basketball, the precise physical demands of this sport are not well described. Therefore, this study aimed to quantify the physical demands of 3 × 3 basketball games according to game outcome and competition phase. Following an observational design, video footage from 27 games were analysed from 104 international 3 × 3 basketball players (n = 52 male and n = 52 female players) belonging to 26 national teams (n = 13 male and n = 13 female teams) during the 2019 FIBA 3 × 3 World Cup. Manual frame-by-frame time-motion analyses were conducted to determine the relative frequency (n · min-1) and duration (% of live playing time) for several physical demand variables to make comparisons according to game outcome (win vs. loss) and competition phase (group games vs. finals games). Linear mixed models for repeated measures and effect size analyses revealed non-significant, trivial-small differences in physical demands between games that were won and lost. Regarding competition phase, male players completed more high-intensity activity (sprinting, high-intensity specific movements, and jumping) but spent a greater proportion of playing time jumping and performing recovery activities (standing/ walking) during finals games than group games (P < 0.05, small), while female players performed more low-intensity activity (jogging and low-intensity specific movements) during group games than finals games (P < 0.05, small). These findings indicate that the physical capabilities of male and female 3 × 3 basketball players may not be the determining factor for team success in games and players can mostly maintain activity outputs across phases of tournament play conducted at the highest international standard.

A ESTABILIDADE DA QUALIDADE PSICOLÓGICA DOS ATLETAS EM GRANDES JOGOS DE BASQUETEBOL

ABSTRACT Introduction Athletes go through psychological wear during competition phases and we should pay attention to the training of athletes’ physical quality, in addition to the exercise of the athlete's psychological quality. Objective This study aims to analyze the relationship between the psychological quality of basketball players and their performance in the game. Methods Basketball players volunteer for the experiment with the “Sixteen Personality Factors Test” scale compiled by American psychologist R.B Cartel to conduct a survey questionnaire. The mathematical statistics method to analyze the data of the research results. Results There were significant differences among the athletes in the broad internal attention and attention pictures (P&lt;0.05). The tenacity, self-control, decision and self-confidence of the analyzed basketball players are at the medium-high level. Conclusion There is a positive correlation between basketball players’ psychological quality and their athletic performance. Basketball players need to develop self-control and overcome psychological barriers during the game. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

Extrinsic doping of Hg2GeTe4 in the face of defect compensation and phase competition

Computation-guided selection of dopants enables the transformation of Hg2GeTe4 from intrinsic to degenerate carrier concentrations and the thermoelectric performance is assessed experimentally.

The Road to Becoming a World Champion in Futsal.

The aim of the current study was to report the training program and monitoring outcomes of the Portuguese national futsal team during the preparation and competition phases of the FIFA Futsal World Cup Lithuania 2021™. For that, the variations in training load and wellness were measured, as well as their relationship. The study followed a retrospective cohort design. For all field training sessions, the volume, exercise structure, and area of play were identified. Player load, session rating of perceived exertion(sRPE), and wellness were collected. Descriptive statistics and Kruskal-Wallis tests were used for comparison purposes. A visualization method was used for load and well-being. No significant differences were observed in the number of training sessions, session duration, and player load between preparation and competitive periods. sRPE showed significantly higher values in preparation than in competition periods (P < .05, d = 0.86) and significant differences between weeks (P < .05, d = 1.08). Wellness showed a general statistical difference between periods (P < .001, d = 1.28) and weeks (P < .05, d = 1.17). The correlation analysis for the overall period revealed a general linear relationship within variables of training load and wellness (P < .001). Variations occurred for preparation and competition periods. The visualization method through quadrant plots allowed us to understand the adaptation of the team and the players over the specific period under analysis. Through this study, it was possible to better understand the training program and monitoring strategies of a high-performance futsal team over a high-level tournament.

Synthesis of Microporous Cobalt Silicate using Organic Template Derived from 2,6-Dimethylpiperidinium Cations: A Potential Precursor for the Preparation of Double Perovskite Cobalt Materials

Abstract: Synthesis of a microporous cobalt silicate was achieved by using 6,10-dimethyl-5-azoniaspiro[4, 5] decane bromide as structure directing agent. And physicochemical characterization was carried out using XRD, SEM, HTEM, TGA, FT-IR, BET-N2, ICP-OES and EDS. ETS-10 like structure framework was present as a competitive phase. Calcination of the cobalt silicate at 500 oC leads to a new structure. The possibility of this material be cobalt oxide was excluded since Bragg reflections at 2θ = 19.2º; 30.3º; 36.9º; 43.7º; 59.2º were absent (JCPDS#80-1538). Both the indexation of the XRD data for the calcined material which has resulted in a tetragonal unit cell (a = b = 10.39 Å and c = 12.21 Å, α = β = γ = 90°, V= 1317.4 Å3) and HTEM data indicated the cobalt silicate can be used as a precursor for the preparation of double perovskite cobalt materials.

Hubbard Bands, Mott Transition and Deconfinement in Strongly Correlated Systems

The problem of deconfinement phases in strongly correlated systems is discussed. In space–time dimension d = 3 + 1, a competition of confinement and Coulomb phases occurs, but in d = 2 + 1 the confining phase dominates owing to monopole proliferation, but Dirac points can change the situation. Combining the Kotliar–Ruckenstein representation and fractionalized spin-liquid deconfinement picture, the Mott transition and Hubbard subbands are treated, general expressions in the case of an arbitrary bare band spectrum being obtained. The transition into a metallic state is determined by condensation of a gapless boson mode. The spectrum picture in the insulating state is considerably influenced by the spinon spin-liquid spectrum and hidden Fermi surface.

Observation of abnormal photoluminescence upon structural phase competence and transition-induced disorder of stable α-FAPbI3

Black-phase formamide lead iodide (α-FAPbI3), considered one of the most important materials for a solar cell application, is generally poorly stable in air, which leads to not only the inability of photovoltaic devices but also the lack of its fundamental optics research. In this paper, we synthesized a stable α-FAPbI3 film by modifying a previously reported method and investigated its temperature- and excitation intensity-dependent photoluminescences (PLs). It is found that at low temperatures, the crystal phase competition process is unusually complicated and out of order. The temperature range of the biphasic coexistence is at least 30 K, and during this process, the PL intensity of either the high-temperature phase (cubic) or low-temperature phase (tetragonal) changes chaotically. After the complete transition to the tetragonal phase, compared with the cubic monophase, PL resulting from the crystal defects is obviously enhanced. Our findings provide a deeper understanding of the complex structural phase transition of halide perovskite and valuable insights into the fundamental optics of α-FAPbI3.

Locomotor activities and subjective load differences between professional youth soccer players and professional development loans: A comparative analysis

This study quantified and compared the weekly locomotor activity and subjective load between elite and development loan youth soccer players registered to a primary club. Development loan players were loaned to a lower-league club and trained part-time with their loan club whilst being available for development fixtures and training with the primary club. Data were collected in 16 squad players and 4 development loan players at loan clubs across a 41 week competitive phase of the 2018/2019 season. Analysis was completed on total distance (m), PlayerLoadTM (au), low intensity running (&lt;14.4 km·h−1, m), running (19.8–24.98 km·h−1, m), sprinting (&gt;24.98 km·h−1, m), accelerations (&gt;2 m·s−2 count) and decelerations (&lt;−2 m·s−2, count). Point estimates for the development loan players consistently showed lower weekly values than squad players for all variables ranging from 5.2% (weekly sRPE) to 16.8% (weekly sprint distance covered). Differences, however, were not found to be statistically significant ( p ≥ 0.07). Variance ranged from 23.6% (weekly distance) to 37.7% (weekly high-intensity accelerations). Although the goals of a development loan are likely to be multifactorial, this is the first study to quantify and compare locomotor activities and subjective loading of players within the development loan environment.

Legacies of failure to win the city of culture: Liminality, civicism and change

The European Capital of Culture Programme and the UK Cities of Culture Programme have emerged as important vehicles in the realisation of the promise of culture led regeneration. However, while value of bidding both in terms of cultural value and public value is well documented, less attention has been given to those cities that loose in their attempts to become Capital of Culture. Drawing on the works of Turner, we conceive of the bidding phase of a competitive cultural mega event competition as a liminal phase; where the ‘old’ rules of cultural organising are put into flux, and where novel or creative solutions can be re-imagined. Using a case study methodology, the paper draws attention to the ways the bidding process shapes the cities, and the legacy effects made possible through engagement in the process. We show how the competitive nature of the bidding process (often with cities competing with their close neighbours), enables a particular form of civic pride, that is, civicism to enrol stakeholder support to ‘do it for the bid’ and set the scene for transformation. We propose that the legacy of bidding is not just about winning (or not) but leveraging the process for sustainable change. We discuss how two places, in competing to host a cultural mega event, used the bid to create change to redress structural and social inequalities. While the emphasis in the current discourse is a ‘winner takes all’, we evidence that this does not do justice to the transformative effect of bidding for those cities that do not go on to host the event. The framework presented in this work offers cities a model to reflect on the transformative potential of bidding for yearlong cultural events. • Mega event bidding process as creative, liminal phase that bring about transformations in the configuration of culture in places. • Local authorities in bidding cities experience altered routines and expansion of expertise in cultural policy and management. • of citizen engagement through civicism and comparison between competing cities is a key feature of the bidding phase. • Increased visibility and internationalisation of the local arts and culture sector shown as key legacy effects of bidding process regardless of outcome of the competition.

Synergetic Ferroelectricity and Superconductivity in Zero-Density Dirac Semimetals near Quantum Criticality.

We study superconductivity in a three-dimensional zero-density Dirac semimetal in proximity to a ferroelectric quantum critical point. We find that the interplay of criticality, inversion-symmetry breaking, and Dirac dispersion gives rise to a robust superconducting state at the charge-neutrality point, where no Fermi surface is present. Using Eliashberg theory, we show that the ferroelectric quantum critical point is unstable against the formation of a ferroelectric density wave (FDW), whose fluctuations, in turn, lead to a first-order superconducting transition. Surprisingly, long-range superconducting and FDW orders are found to cooperate with each other, in contrast to the more usual scenario of phase competition. Therefore, we suggest that driving charge neutral Dirac materials, e.g., Pb_{x}Sn_{1-x}Te, through a ferroelectric quantum critical point may lead to superconductivity intertwined with FDW order.

Biomechanical properties of the discus throw: analytical case study of the Paralympic record holder in the F33 category

PurposeThe study aims to determine the kinematic and kinetic characteristics of the discus throwing competition for the Paralympic record holder in the F33 category, the champion Hani Al-Nakhli, silver medalist in the London 2012 Paralympic and the World Champion in the discus throw (height: 1.71 m, weight: 96 kg, age: 35 years, training age: 14 years). MethodsThe player's performance was photographed during a training session in the middle of the competitive phase of the 2021/2022 season using three GoPro Hero 6 cameras, each set at a frame rate of 60fps. A video-based motion and skill analysis tool for Windows was used to choose the best approach for creating a 3D biomechanical analysis. ResultsThe values of the Paralympic champion were presented and discussed, and the researchers improved the player's ability to work—increasing the acceleration distance of the disc by up to 1.85 m with an acceleration within a period of 0.40 s. Thus, high-speed rates of up to 16.77 m s−1 was achieved during the launch, with the disposal of the disc at an angle of clearance of 37° and a starting height of 1.36 m, resulting in 27 m. The values of the kinetic analysis represented the need to increase the tangential potential energy of the body by 1884 J during disposal while increasing the tangential kinetic energy of the body by a value of 9.93 J. This is achieved by increasing the rotational kinetic energy of the body of the player to reach high achievement distances for class F33. It is recommended to use the results of the variables in the training process to prepare champions for the discus throwing competition.

Competing states in the two-dimensional frustrated Kondo-necklace model

The interplay between Kondo screening, indirect magnetic interaction and geometrical frustration is studied in the two-dimensional Kondo-necklace model on the triangular lattice. Using infinite projected entangled pair states (iPEPS), we compute the ground state as a function of the antiferromagnetic local Kondo interaction $J_K$ and the Ising-type direct spin-spin interaction $I_z$ . As opposed to previous studies, we do not find partial Kondo screening (PKS) in the isotropic limit $I_z = 0$ but the same behavior as in the unfrustrated case, i.e. a direct phase transition between the paradigmatic phases of the Doniach competition: (i) a disordered phase consisting of local spin-singlets at strong $J_K$ and (ii) a magnetically ordered phase at weak $J_K$ . For $I_z > 0$, we find a PKS ground state but again in opposite to previous studies, we find that the PKS ground state is in strong competition with a second ground state candidate not found before. This state is characterized by a strongly polarized central spin in each hexagon and its anti-parallel, weakly polarized (i.e. partially screened) neighbors. We name it central spin (CS) phase.

Realization of high-quality Sr4Fe6O13 epitaxial film and its phase competition with SrFeO2.5

Oxides with heterostructures or superlattices have been a hot topic for a long time owing to blowout phenomena and broad applications in spintronics, ferroelectric devices and superconductors. The Sr4Fe6O13-type superlattice, a weak ferromagnet with unique electron-ion hybrid conductivity, has recently received much attention. However, due to the lack of a high-quality single crystal for research, the origin of its ferromagnetism and conductivity still needs to be addressed. Epitaxial films are an excellent method for obtaining high-quality single crystals with definite orientations and substrate-induced strains. In this study, Sr4Fe6O13 films are grown using pulsed laser deposition (PLD). A systematic investigation of the growth conditions is carried out to synthesize pure and high-quality Sr4Fe6O13 epitaxial films. A phase diagram is drawn to illustrate the effects of the growth conditions on the phases of the films after a series of experiments were conducted under various growth conditions. Based on the density functional theory calculations’ results, which strongly agree with the phase diagrams acquired from experiments, the competition of the formation of Gibbs free energies between Sr4Fe6O13 and SrFeO2.5 is addressed. An oxygen-deficient environment inhibits the growth of Sr4Fe6O13 but favors SrFeO2.5. The as-grown high-quality Sr4Fe6O13 epitaxial film is fully strained, and scanning transmission electron microscopy confirms its microstructure. Our findings can shed light on the development of other films with similar layered superlattice structures and investigate their intrinsic properties.