Arm Length Research Articles

The last generation: F3 of Echinometra sea urchins under experimental climate change

Ocean warming and acidification are a threat to calcifying marine invertebrates such as Echinoderms. Transgenerational plasticity may allow animals to respond to these conditions, but few studies exposing marine invertebrates to climate stressors over multiple generations exist. Here, data from the final (F2 post-settlement, F3 larvae and juveniles) generations in a long-term (> 6 yrs) experiment on the tropical sea urchin Echinometra sp. A. This commenced with exposing wild collected animals (F0 generation) and subsequent generations (larvae and adults both for F1 and F2) to control (present-day ambient) and climate change (CC) conditions (2 °C above ambient temperatures, 940 ppm pCO2). Survivorship in all F2 treatments (ranging from all generations being held at ambient conditions to all at elevated conditions) was high (> 50%). Some significant differences in survivorship existed among treatments, although there was no apparent relationship to CC conditions exposure time. There was also no difference in size among treatment groups in the F2 sea urchins up to 720d post-settlement. As in previous generations, the largest effect on adults was that males exposed to CC conditions have reduced reproductive potential, and there was a significant negative relationship with the number of generations exposed to future ocean conditions and spawning performance. Effects were extreme, in that we could only raise larvae from the control treatment, or those individuals kept for 0.5 generations (only F2 adults under climate change conditions). Larvae from both parental groups only reached settlement when raised under control conditions. Larval morphology also responded to treatment (reduced arm length under CC conditions) and exhibited negative parental effects (smaller arm and body lengths from parents under CC conditions). Thus, negative parental effects observed in earlier publications did not diminish over the following generations but, in some traits, increased. We therefore detected no evidence of transgenerational acclimation to future ocean conditions.

Numerical Modelling of the Punching Shear Response of Shearhead Connections between a CFT Column and a Flat Reinforced Concrete Slab

In this article, the punching shear response of shearhead connections between a Reinforced Concrete (RC) flat slab and interior Concrete-Filled steel Tubular (CFT) columns under static load is investigated by using a 3D nonlinear finite element modelling approach. The accuracy of the numerical model is verified against recent experimental results by comparing the results of the load–displacement relationship, failure models and cracking patterns. Based on validated numerical models, parametric investigations are conducted to examine the effects of slab thickness, concrete compressive strength, length of shearhead arm, size of shearhead cross section and flexural reinforcement ratio on the punching shear response of the connections. Then, some recommendations are given for the design of the effective parameters of shearhead connections, particularly focusing on the effective length and cross-section size of shearhear arms. Finally, a design equation considering the effect of the effective length of shearhead arms and flexural reinforcement ratio is proposed to predict the punching shear strength of shearhead connections. The comparison of punching shear strengths predicted by the proposed equation and some design codes shows that the proposed equation can predict the punching shear strength of shearhead connections more accurately than those from ACI 318-14 and Eurocode 2.

A detailed karyological investigation of three endemic Cobitis L. 1758 species (Teleostei, Cobitidae) in Anatolia, Türkiye.

Comparative cytogenetics is a vital approach for diagnosing chromosome abnormalities and identifying species-specific patterns. In this study, chromosomal analysis of three Anatolian endemic Cobitis species was performed. Conventional cytogenetic techniques such as Giemsa staining, C-banding and Ag-NOR staining were applied, followed by measurements of chromosome arm lengths including analysis of the measured data. The diploid chromosome number, 2n = 50, was determined for all three species. The karyotype formulas were as follows: four pairs of metacentric, five pairs of submetacentric, and 16 pairs of subtelo-telocentric chromosomes in Cobitis bilseli; 11 pairs of metacentric, seven pairs of submetacentric, and seven pairs of subtelo-telocentric chromosomes in C. fahireae; and four pairs of metacentric, four pairs of submetacentric, and 17 pairs of subtelo-telocentric chromosomes in C. turcica. Dark C-bands were observed on the pericentromeres of nearly all chromosomes in C. bilseli and C turcica, whereas light C-bands appeared on the pericentromeres of some chromosomes in C. fahireae. Silver-stained metaphases revealed signals on the short arm of a submetacentric chromosome pair in C. fahireae (each homologous chromosome carries one signal), while in C. bilseli and C. turcica, Ag-NOR signals were detected on the long arm of a single metacentric chromosome (only one homologous chromosome carries the signal, and the signal-carrying chromosome is the largest chromosome in the karyotype). This study provides new cytogenetic data consistent with the phylogenetic distances between the studied species, indicating pericentric inversions and/or translocations that govern the formation of Cobitis karyotypes.

DEVELOPMENT OF TRANSFER PRICING REGULATIONS IN INDONESIA

This research driven by the urgency to understanding the massive improvement of transfer pricing regulations in Indonesia. Directorate General of Taxes (DGT) have adjusted along with the advancement of macroeconomic, business field, cross border trade, and domestic needs. This study aims to describe the development of transfer pricing regulations in Indonesia, since it was first enacted in 1983. The analysis covers three main topics, which are the implementation and examination of arm's length principle, transfer pricing documentation, and advance pricing agreement. This research used qualitative methodology, particularly analytical descriptive approach. Analytical descriptive performed by analyze, capture, and summary a set of regulations, then provide them in the text containing important provision from each regulation. The result shows that there has been a significant development in transfer pricing regulation in Indonesia. Since the first time enacted, there are eight regulations concerning arm’s length principle, three regulations concerning TP Doc, and five regulations concerning advance pricing agreement which enacted sequentially. Those have provided more detailed rules and fulfilled stakeholders' needs. Novelty of this research can be seen through the comprehensive inventory of transfer pricing regulations in Indonesia, which can provide broad explanation for readers. This research may contribute to enrich the transfer pricing literature for academics. Besides, by describe the whole transfer pricing regulations in Indonesia, this research may also contribute to broaden taxpayer’s understanding and improve service quality of tax authority. From this research, it can be concluded that development of the transfer pricing regulations has provided legal certainty and efficiency for taxpayers and DGT in its implementation.

Basic Anthropological Characteristics of Elite U17 Youth Serbian Female Volleyball Players According to Playing Position

This study examines the differences in the anthropometric characteristics and motor abilities of young elite female volleyball players depending on their playing position. This study was conducted with 114 U17 female players of the Serbian national team (age: 15.4 ± 0.4 years; body mass: 65.8 ± 7.8 kg; height: 176.8 ± 7.7 cm). All participants had at least four years of volleyball experience. A one-way ANOVA revealed significant differences (p ≤ 0.05) in body mass (BM), body height (BH), body mass index (BMI), one-arm standing reach (1ARS), two-arm standing reach (2ARS), arm span, a medicine ball throw (MT), standing long jump (SLJ), squat jump (SJ), countermovement jump without an arm swing (CMJ), 5 m sprint (S5), 15 m sprint with a flying start (S15), 20 m sprint (S20), and t-test (TT). The results show that a player’s position significantly impacts their anthropometric characteristics and motor abilities, with liberos requiring agility and flexibility, while middle blockers and opposite hitters focus on strength and explosiveness. Outside hitters and setters achieved high results in jump tests, while outside hitters, although agile, had slightly lower results in the long jump. The results confirm that BH and BM, 1ARS, 2ARS, arm span, explosive power, agility, speed, and flexibility significantly impact performance, indicating that a player’s position affects their anthropometric characteristics and motor abilities.

The Role of the GH/IGF Axis in Statural Growth and Harmonious Body Proportionality: In Search of Vitruvian Man.

In this epidemiological, non-interventional study, we compared the anthropometric measurements and body proportions of an Ecuadorian cohort of adult subjects with GH insensitivity (GHI) due to a homozygous mutation at codon 180/exon 6 of the GHR, to their carrier and non-carrier relatives, and to non-carrier unrelated controls. We also investigated the relations between serum IGF-I concentrations and auxological determinations. In this cohort of 201 adults, gender-specific distributions of height (Ht), lower segment, upper segment, arm span, head circumference (HC), hand and foot length were lower in the GHI subjects than in the other groups. The GHI individuals had the lowest lower segment/Ht, the highest upper segment/Ht, the lowest arm span/Ht and the highest head circumference/Ht ratio. Hand and foot length/Ht ratios were not uniformly affected. Serum IGF-I concentration displayed a positive logarithmic correlation with all body measurements but were negatively correlated with the head circumference/Ht ratio. These findings indicate that subjects homozygous for the GHR mutation have disharmonious body proportions due to abnormal GH/IGF-I action on the growth of the long bones. Contrary to common assumptions, disruption of the GH-IGF axis results in disproportionality and disharmonious growth.

Additive Manufacturing Oriented Parametric Design Automation of Adaptive Joint System for an Irregular Form Gridshell Structure

In architectural engineering, triangular tessellation using polygon mesh topology is one of the commonly used computational geometric approaches to simplify a free curved building façade into flat triangular facets and their subsequent straight edges. In such a façade system, exterior panels are supported by a network of profiles that correspond to their edges hidden behind the panels at an offset distance. A group of profiles, derived from the edges common to a node point of tessellated panels (i.e., the outermost panels enveloping the building), may dislocate from each other when offset from their original locations due to non-coplanar alignment and unique offset directions and distances. This dislocation problem gives rise to geometric complications in nodal connector design in addition to varying in the connected profile count and orientations. Design considerations regarding the effects of ’offset vertex dislocation’ (i.e., the dislocation of the edges when it offsets from the original topology due to incoherent normal direction) should incorporate proper variables in the correct sequence based on a fundamental understanding that causes the dislocation problem. However, it is very often these topological problems pertaining to offset that are neglected, leading to subsequent design flaws. Such oversights diminish the inherent strengths of DfMA (design for manufacture and assembly) and design automation. This study develops a computational mathematical approach aimed at addressing the geometric complexities in nodal connector design. It focuses on two main areas: the precise positioning of substructure profiles essential for the design and a design automation approach that minimizes the length of the nodal connector arms to enhance 3D printing productivity. A life-scale proof-of-concept structure based on an automated parametric design process that implements the research findings demonstrates the application, incorporating 3D-printed PA12 (Polyamide-12) nodal connectors.

Fluid balance of female para hockey players during simulated competition.

The purpose of this study was to characterize the hydration habits and fluid balance of female para-ice hockey players. Fifteen players [5 defense (D), 8 forwards (F), and 2 goalies (G)] volunteered to participate in the study (age: 26.3 ± 10.9 y; ht:155 ± 11 cm; arm length: 65 ± 8 cm; leg length: 88 ± 11 cm; trunk length: 66 ± 14 cm). Players were weighed pre- and postgame, while fluid intake and individual playing time (PT) was monitored throughout the game. On average, athletes arrived hydrated to the game (USG 1.019 ± 0.006) with 40% of players arriving dehydrated (USG >1.020). Mean playing time for forwards was 11:47-28:49 min:s (18:52 ± 5:48 min:s) and for defence 13:10-18:24 min:s (15:10 ± 2.05 min:s). Sweat loss was 0.96 ± 0.64 L (0.10-2.50 L) which exceeded net fluid intake (0.61 ± 0.37 L). Mean BM loss was 0.44 ± 0.9% (-2.1 to +0.9%) with 4 of 15 players (2 D, 1 F, 1 G) losing between 1.4 and 2.1% BM. Players preferred to drink water during the game compared to a carbohydrate electrolyte solution. 60% of athletes arrived hydrated to the game and drank enough fluid to prevent a BM loss <1%. Of note is that 40% of players arrived at the arena mildly dehydrated based on USG, and despite abundant opportunities to drink fluid during the game, 25% of players lost >1.3% BM due to sweat loss which may compromise physical and cognitive performance.

A novel pendulum-like deformation-limited piezoelectric vibration energy harvester triggered indirectly via a smoothly plucked drive plate

Vibration energy harvesting using the piezoelectric effect is emerging as a promising sustainable energy solution for micro-electromechanical systems and wireless sensor networks. Nevertheless, the advancement of piezoelectric vibration energy harvesters has been hindered by reliability issues stemming from piezoelectric material damage due to excessive deformation. To address this challenge, a pendulum-like deformation-limited piezoelectric vibration energy harvester triggered indirectly via a smoothly plucked drive plate (D-LPVEH) is proposed. The D-LPVEH effectively constrains the maximum deformation of the piezoelectric beam, enabling unidirectional deformation and enhancing reliability even under unexpected impacts, by introducing a drive plate. Simulation and experimental findings both validate the efficacy of limiting the piezoelectric beam’s deformation by integrating the drive plate structure. Besides, the D-LPVEH has a good environmental adaptability and designability, which means D-LPVEH can work in different frequency ranges by adjusting proof mass and mass arm length, even at low frequency environmental vibrations of a few Hertz. Moreover, the D-LPVEH demonstrates a peak output power of 0.77 mW at a mere 5.6 Hz, with an optimal load resistance of 100 kΩ, and can consecutively illuminate a minimum of 100 commercial blue LEDs. The D-LPVEH has demonstrated to have good power generation and high reliability. This design will provide a reference for the research on improving the reliability of PVEH.

How to arrange the robotic environment? Leveraging experience in both motion planning and environment optimization.

This study presents an experience-based hierarchical-structure optimization algorithm to address the robotic system environment design problem, which combines motion planning and environment arrangement problems together. The motion planning problem, which could be defined as a multiple-degree-of-freedom (m-DOF) problem, together with the environment arrangement problem, which could be defined as a free DOF problem, is a high-dimensional optimization problem. Therefore, the hierarchical structure was established, with the higher layer solving the environment arrangement problem and lower layer solving the problem of motion planning. Previously planned trajectories and past results for this design problem were first constructed as datasets; however, they cannot be seen as optimal. Therefore, this study proposed an experience-reuse manner, which selected the most "useful" experience from the datasets and reused it to query new problems, optimize the results in the datasets, and provide better environment arrangement with shorter path lengths within the same time. Therefore, a hierarchical structural caseGA-ERTC algorithm was proposed. In the higher layer, a novel approach employing the case-injected genetic algorithm (GA) was implemented to tackle optimization challenges in robot environment design, leveraging experiential insights. Performance indices in the arrangement of the robot system's environment were determined by the robotic arm's motion and path length calculated using an experience-driven random tree (ERT) algorithm. Moreover, the effectiveness of the proposed method is illustrated with the 12.59% decrease in path lengths by solving different settings of hard problems and 5.05% decrease in easy problems compared with other state-of-the-art methods in three small robots.

Suppression of clock-jitter noise and laser phase noise in arm locking

Abstract Arm-locking technique has been a focus of attention as one of the means to suppress the laser phase noise in space-based gravitational wave detector. The main idea of the arm-locking technique is to transfer the stability of the detector arm length to laser frequency by introducing a feedback control loop. Generally, laser phase noise will be suppressed by an amount similar to the magnitude of the controller gain. However, on the one hand, clock-jitter noise and optical bench motion noise, as the noise floor of the arm-locking technique, need to be suppressed. On the other hand, limited by the Doppler frequency pulling, the gain of the controller generally cannot be too large. It means that even if we do not consider clock-jitter noise and optical bench motion noise, it is difficult to suppress laser phase noise below the noise floor only by arm-locking technique. In this work, we combine self-referenced optical frequency combs and arm-locking technique to generate clock signals that are coherently referenced to the closed-loop laser beams, so that the clock-jitter noise is also suppressed by about the level of controller gain. We conduct a simulation on the above configuration, and the results show that the performance of the arm-locking is no longer limited by clock-jitter noise in the low-frequency band. To address the issue of insufficient laser phase noise suppression by the arm-locking technique, we further investigate time-delay interferometry (TDI) combinations under outputs of arbitrary arm-locking configurations. We obtain the equations for eliminating laser phase noise. To ensure that the TDI combinations can directly operate in the time domain, we derive a restricted solution space by assuming a specific form for the solutions.

An enhanced broadband piezoelectric energy harvester via elastic amplification structure for multidirectional vibration

Abstract Vibration energy harvesting using a piezoelectric mechanism has significant potential for powering wireless sensors. However, most current vibration energy harvesters face limitations such as bidirectionality, narrow bandwidth, and high operating frequencies. To address these issues, we propose an enhanced broadband piezoelectric energy harvester utilizing an elastic amplification structure for multidirectional vibration (EB-PVEH). By utilizing the multidirectional rotation capacity of the excitation block and the amplified foundation excitation provided by springs, the EB-PVEH effectively captures broadband vibrations in 2D space under low-frequency excitation. Additionally, its design features long-term durability, as the piezoelectric beams are smoothly excited by the pendulum-induced motion of the block without a tip mass. The practical feasibility and the impact of structural parameters on the output behavior of EB-PVEH were investigated through theoretical analysis and experimental testing. The results revealed that the introduction of springs dynamically amplified the harnessed electrical power output. Moreover, EB-PVEH could harvest the multidirectional vibration, and it exhibited different power-generating characteristics in various directions. Furthermore, the resonance frequency could be efficiently tuned by adjusting the flexible arm length and proof mass, with different optimal arm lengths identified for each vibration direction to maximize working bandwidth. The harvester achieved an optimal output power of 3.98 mW. Practical applications, such as charging a capacitor by driving an e-bike or a bike, demonstrate the potential of the proposed harvester to provide power for micro-electrical devices.

Characterizing gravitational wave detector networks: from A♯ to cosmic explorer

Abstract Gravitational-wave observations by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo have provided us a new tool to explore the Universe on all scales from nuclear physics to the cosmos and have the massive potential to further impact fundamental physics, astrophysics, and cosmology for decades to come. In this paper we have studied the science capabilities of a network of LIGO detectors when they reach their best possible sensitivity, called A#, given the infrastructure in which they exist and a new generation of observatories that are factor of 10 to 100 times more sensitive (depending on the frequency), in particular a pair of L-shaped Cosmic Explorer observatories (one 40 km and one 20 km arm length) in the US and the triangular Einstein Telescope with 10 km arms in Europe. We use science metrics derived from the top priorities of several funding agencies to characterize the science capabilities of different networks. The presence of one or two A# observatories in a network containing two or one next generation observatories, respectively, will provide good localization capabilities for facilitating multimessenger astronomy and precision measurement of the Hubble parameter. Two Cosmic Explorer observatories are indispensable for achieving precise localization of binary neutron stars, facilitating detection of electromagnetic counterparts and transforming multimessenger astronomy. Their combined operation is even more important in the detection and localization of high-redshift sources, such as binary neutron stars, beyond the star-formation peak, and primordial black hole mergers, which may occur roughly 100 million years after the Big Bang. The addition of the Einstein Telescope to a network of two Cosmic Explorer observatories is critical for accomplishing all the identified science metrics. For most metrics the triple network of next generation terrestrial observatories are a factor 100 better than what can be accomplished by a network of three A# observatories.

Quandaries of Trying to Do Good-The Adequacy of the WHO FENSA Regulations.

The World Health Organization's (WHO) Framework of Engagement with Non-State Actors (FENSA), established in 2016, is designed to enhance transparency, impartiality, and conflict-of-interest safeguards by setting rigorous guidelines for WHO's interactions with private entities, particularly those in high-risk industries such as tobacco, alcohol, and arms. This paper briefly reviews the implementation and impact of FENSA, observing that, despite these safeguards, its application in academic contexts poses specific challenges. Universities, often reliant on diverse funding sources, may find the rules restrictive and misaligned with independent funding needs. The creation of the WHO Foundation in 2020 further complicates this landscape by enabling engagements with previously restricted private sector entities through an "arm's length" model. The authors advocate for a reassessment of FENSA to resolve inconsistencies and support essential academic collaborations, while upholding WHO's commitment to ethical standards.

Numerical study of magnesium dendrite microstructure under convection: Change of dendrite symmetry

Besides diffusion and capillary, convection which is unavoidable under terrestrial condition has remarkable effects on the microstructure evolution during solidification. In this study, a phase-field lattice-Boltzmann model, accelerated by state-of-the-art parallel-adaptive mesh refinement algorithm, is solved to investigate the morphological evolution of the Mg-Gd dendrite under convection. The lengths of the dendrite primary arms are quantified to analyze the asymmetric dendrite patterns under convection. The effects of the multiple factors including the orientation angle, the flow intensity, and the undercooling are elucidated, and the relation between the length ratios and the three independent factors is established through multiple regression analysis. The upstream-downstream arm length difference and the included angle between the primary arms are characterized to illustrate the effect of convection on the evolution of the Mg-Gd dendrite. The 3D morphological selection, together with algorithm performance tests, is further discussed to elucidate the change of morphological symmetry under different growth conditions and to demonstrate the robustness of the numerical scheme. Deep understanding of the synergy between convection-induced solute transport and undercooling-driven growth, which largely determines the morphological selection, can assist guidance for the prediction and control of the magnesium alloy microstructures.

Blackness, linguistic nationalism, and postcolonial class inequality in Haiti

AbstractThis ethnographic examination of a binary linguistic hierarchy in Haiti shares the critical terrain of Viranjini Munasinghe's unpacking of Caribbean creolization theory. It is a grounded inquiry into a problematic of ontology that inheres in techniques of making non‐white identities deployed by Caribbean privileged people of color at arm's length from a European colonial heritage that underpins their privileged class positions. Borrowing Munasinghe's analytic concept of theory made schizophrenic by ideology, the investigation reveals Haiti's francophone minority ideologically utilizing Haitian Creole as a black‐nationalist symbol in its domination of the monolingual Creole‐speaking majority. The ideological move devalues Creole while elevating French in the reproduction of class inequality. The linguistic schizophrenia undermines the theoretical nation‐building logic of Creole as national language. Failing practical validation of Creole in all spheres of Haitian life, I conclude, claims on the state and civil society by Haiti's vast monolingual Creole‐speaking majority cannot logically be validated.

Comparison of dynamic balance indicators using the Star Excursion Balance Test method in men of various types of martial arts with left- and right-sided motor asymmetry

Purpose: to perform a comparison of the Star Excursion Balance Test indicators in men of various types of martial arts with left- and right-sided motor asymmetry. Material and methods. The results of the study were obtained at the Ivan Boberskyi Lviv State University of Physical Culture at the Department of Fencing, Boxing and National Martial Arts in the period October-December 2023. Qualified male martial artists aged 18-22 in the number of 84 participated in the collection of experimental material: 11 representatives WKF karate (including 1 left-hander), 12 members of fencing (including 2 left-handers), 9 representatives of hopak hand-to-hand combat (including 1 left-hander), 31 representatives of boxing (including 12 left-handers), 21 representatives of Kyokushinkai karate (among whom there was 1 left-handed person). Research methods: analysis of literary sources and materials from the Internet; survey (questionnaire); measurement of anthropometric indicators of athletes (height, body weight, length of arms and legs); measurement of Star Excursion Balance Test (SEBT); methods of mathematical statistics. Results: right-handed martial artists (n=67) had an anthropometric advantage over left-handed martial artists (n=17): height – 178.1 cm versus 177,5 cm, respectively, body weight – 70,9 kg versus 66,8 kg, length arms – 76,7 cm vs. 73,9 cm (P&lt;0,05), leg length – 95,0 cm vs. 91,8 cm. Comparison of SEBT indicators revealed: left-handed group has better SEBT indicators in almost all positions, as on the left side of the body, as well as on the right. When comparing indicators of all 8 positions of SEBT of the left leg in right-handed and left-handed players, it was found that left-handed players had significantly (P&lt;0,05) better indicators in positions 6 and 7. Left-handed martial artists demonstrated significantly (P&lt;0,05) the best SEBT indicators in positions 6, 7, 8 of the right leg than right-handed martial artists. SEBT indicators of both right and left arms showed that positions 7, 8 of both left and right arms were significantly (P&lt;0,05) better than those of right-handers. A separate phenomenal result is the specificity of passing the SEBT test by left-handed athletes: their results are significantly (P&lt;0,05) better in the most difficult positions – 6, 7, 8, and in each of the four limbs of the body, regardless of motor asymmetry. Conclusions. The results of the work demonstrated phenomenal SEBT indicators in left-handed martial artists, compared to right-handed martial artists. This phenomenon is observed in all SEBT indicators of the lower and upper limbs of the left and right sides of the body: indicators of all SEBT positions in left-handed athletes are better than in right-handed athletes. Lefties reliably dominate in the most difficult positions of the test – 6, 7, 8, both in the girdle of the upper limbs and in the balance and flexibility of the lower limbs, regardless of asymmetry. This phenomenon is observed against the background of left-handed athletes lagging behind right-handed athletes according to anthropometric indicators. In view of the above, we assume that left-handed athletes have special properties of neuromuscular activity that require special in-depth research.

Structural dynamic characteristics of vertical axis wind and tidal current turbines

Vertical axis turbines have received great attention in both offshore wind and tidal current energy communities considering their advantages of economic design and unidirectional operation. However, their commercialization process is rather slow compared with the development of horizontal axis turbines due to technical challenges resulting from higher loads from unsteady aero/hydrodynamic forces, centrifugal forces and gravity of the structures. These are mainly because, while the inherent unsteady tangential pulls and fatigue loads intensify the structural vibration, aggravating structural safety and fatigue life, the relationship between the geometric parameters and the structural responses of blades remains unclear. Therefore, in order to clarify this issue, in this study, we focus on the modal and transient analysis of vertical axis turbines using multi-body dynamics, geometrically exact beam theory and detached eddy simulation. We find that the natural frequency of the rotor is directly related to the ratio of blade length and arm length. The effect of arms cannot be ignored in the structural analysis of the turbine. Moreover, an increase of blade length intensifies the deformation and vibration of the turbine’s structure, making the turbine more prone to fatigue failure. This article is expected to extend the existing knowledge of wind and tidal current turbines and provide a reference for choosing proper design parameters and developing suitable-capacity vertical axis turbines.

ФУНКЦИОНАЛЬНЫЙ ПРОФИЛЬ ГИМНАСТОВ ВЫСОКОЙ КВАЛИФИКАЦИИ

The purpose of the research was to determine the model functional profile of highly qualified gymnasts. Methods and organization of the research. The main research methods were anthropometry, stabilometry, bioimpedance analysis of the body and determination of anaerobic power using the Wingate test (foot and hand), implemented within the framework of the organization of a mobile laboratory during the I All-Russian Spartakiad of the strongest athletes of Russia in summer sports: artistic gymnastics competitions. Pedagogical observation of the competitive activities of the best gymnasts (Honoured Master of Sports (HMS), Master of Sports of International Class (MSIC), Master of Sports (MS)) was conducted at these competitions (n=15). The gymnasts were divided into three groups: group 3 - gymnasts-masters of sports (n=8), group 2 - gymnasts, members of the Russian national team, winners of championships and cups of Russia (MS, MSIC) (n=5), group 1 - elite gymnasts, leaders of the Russian national team, including 1 Olympic champion (MS, HMS) (n=2). The functional profile was determined by finding relationships between sports results and functional parameters of the gymnasts; comparison between the groups was carried out using one-way analysis of variance. Research results and their discussion. Differences in anthropometric indicators were revealed in three groups of gymnasts: group 1 has the highest index of torso length, while this group has the lowest index of relative arm length. Group 2 has a proportional body type. The anaerobic performance indicators of the gymnasts of group 1 are statistically significantly different from those of the gymnasts of groups 3 and 2 (p≤0.05), with the peculiarity of group 1 being the registration of the absolute peak power parameter PP (W), shown by the arms (982.50±16.60), which is greater than the similar indicator shown by the legs (817.85±60.45), when performing the Wingate test (5 sec). The gymnasts of group 1 also differ significantly in terms of body composition indicators, especially in terms of the proportion of active body mass (67.65%±1.05). Conclusion. As a result of the research, functional profiles of elite gymnasts, gymnasts of the national team and gymnasts-masters of sports were determined, which can be used as a guide when interpreting the results of functional diagnostics of gymnasts and concluding about their prospects from the functional component.

Optimizing talent identification and development in finswimming athletes: Challenges and innovative solutions

The main objective of this article is to highlight the components of anthropometry, biomotor abilities, and skills related to the identification and development of young athletes’ talent and to propose several possible solutions that practitioners and researchers can consider to optimize talent identification. A total of 60 Intermediate First students were recruited and tested for anthropometry, biomotor abilities, and skills. The subjects selected for this study were chosen based on the criteria that they had participated in extracurricular swimming activities and could swim freestyle for 50 meters. The results show that anthropometry is an important factor, with the following values: height (TB) 0.895a, lean body weight (BBTL) 0.832a, leg length (PTU) 0.819a, hand length (PTA) 0.738a, arm span (RL) 0.705a, and body weight (BB) 0.682a. The biomotor values are as follows: explosive power of leg muscles (DLOT) 0.896a, left ankle dorsiflexion (ADFKI) 0.797a, leg muscle strength (KOT) 0.701a, right ankle dorsiflexion (ADFKA) 0.683a, explosive power of arm muscles (DLOL) 0.638a, arm muscle strength (KOL) 0.637a, left ankle plantar flexion (APLKA) 0.514a, and right ankle plantar flexion (APLKI) 0.545a. Several skill characteristics that significantly influence bi-fin swimming athletes’ talents include breathing using a snorkel (BMS) 0.579a, swimming 100 meters using a snorkel and fins (B100) 0.532a, and underwater kicking for 15 meters (UW15) 0.500a. These findings provide proof that components of anthropometry (BB, TB, PTU, PTA, RL, and BBTL), biomotor abilities (KOT, ADFKI, ADFKA, APFKI, APFKA, KOL, DLOT, and DLOL), and skills (BMS, B100, and UW15) related to the identification and development of young athletes’ talent in finswimming (bi-fins) can provide solutions and a strong foundation to support the development of athletes’ talent. However, further research is required to confirm and validate this finding.