Pitch Dimensions Research Articles

Optimization of Fuel Enrichment and Reactor Core Pitch Dimension in Hydride Microreactor using NSGA-II Method and OpenMC Calculation

Abstract This study focuses on the design optimization of a hydride microreactor, aimed at supporting the equitable development of electricity in remote regions of Indonesia. Its compact design, inherent safety properties, and independence from the conventional electric grid make this microreactor concept suitable for electrifying even the most inaccessible areas. Current research investigates various aspects of the hydride microreactor design, employing a standard reactor core pitch dimension of 2.4 cm and fuel enrichment of 12%. It is crucial to operate the reactor using specific concentrations of Gadolinia burnable poison to enable a shutdown in the event of a stuck rod. By optimizing only the pitch dimension and fuel enrichment, the reactor can be simulated relatively quickly without the need for burnup calculations. Ideal configuration aims for lower enrichment, an extended fuel cycle, and a relatively low power peaking factor (PPF). The optimization process utilizes the Non-dominated Sorting Genetic Algorithm – II, with the neutron multiplication factor (keff) and PPF as primary objectives. Fuel cycle and feedback reactivity are the sub-objectives that are used to identify the optimal solution from the Pareto front. The calculation process of keff, PPF, fuel cycle, and feedback reactivity coefficients for specific pitch dimensions and fuel enrichment are done by utilizing the OpenMC Monte Carlo code. The optimal configuration is obtained through four generations of NSGA-II, featuring a reactor core pitch of 2.1 cm and fuel enrichment of 10.4%. This configuration yields a keff value of 1.0712049 and a PPF value of 2,0728 at the Beginning of Life (BOL). Remarkably, this configuration enables safe operation without using burnable poison for a continuous period of 12 years, generating 1 MW of thermal power. Emphasizing the reduction of fissile material is also essential to enhance the inherent safety of the reactor.

Body mass index associated with respiration predicts motion in resting-state functional magnetic resonance imaging scans.

Decreasing body mass index (BMI) reduces head motion in resting-state fMRI (rs-fMRI) data. Yet, the mechanism by which BMI affects head motion remains poorly understood. Understanding how BMI interacts with respiration to affect head motion can improve head motion reduction strategies. A total of 254 patients with back pain were included in this study, each of whom had two visits (interval time = 13.85 ± 7.81 weeks) during which two consecutive re-fMRI scans were obtained. We investigated the relationships between head motion and demographic and pain-related characteristics-head motion was reliable across scans and correlated with age, pain intensity, and BMI. Multiple linear regression models determined that BMI was the main determinant in predicting head motion. BMI was also associated with two features derived from respiration signal. Anterior-posterior and superior-inferior motion dominated both overall motion magnitude and the coupling between motion and respiration. BMI interacted with respiration to influence motion only in the pitch dimension. These findings indicate that BMI should be a critical parameter in both study designs and analyses of fMRI data.

Can The Pitch Dimension Influence the Physical Fitness Adaptations Induced by Small-Sided Training Programs Added to Regular In-Field Training? A Randomized Controlled Study in Youth Soccer Players.

Small-sided games (SSGs) are frequently utilized in training settings to elicit specific stimuli that can promote physical fitness adaptations over time. However, various task constraints, such as pitch dimensions, can significantly influence both the acute external and internal load responses. Thus, understanding the impact of different pitch dimensions on physical fitness adaptations is crucial. This study sought to compare the physical adaptations induced by an SSG-based program utilizing more elongated pitches (SSGlw2; length-to-width ratio: 2.0) versus less elongated pitches (SSGwl1; length-to-width ratio: 1.0) on the Yo-Yo intermittent recovery test level 1 (YYIRT), and 30-meter sprint. This study employed a randomized controlled design. Forty-eight male soccer players (16.4 ± 0.6 years) participated. These players were randomly allocated to two experimental groups (N = 16, SSGlw1; N = 16, SSGlw2) and underwent two weekly additional training sessions over an 8-week period, while a group of 16 players continued with their regular in-field sessions as a control group. Evaluations were conducted before and after the intervention period. Significant interactions time u group were observed in regards YYIRT (F = 15.857; p < 0.001; = 0.413) and 30-m sprint test (p < 0.001). Between-group differences on YYIRT were found in post-intervention (p < 0.001), on which SSGlw2 (p < 0.001) and SSGlw1 (p < 0.001) were significantly greater in comparison to control group. Additionally, between-group differences on 30-m sprint were found in post-intervention (p < 0.001), on which SSGlw2 was significantly better than SSGlw1 (p < 0.001) and control group (p < 0.001). Coaches are advised to prioritize the use of more elongated pitch sizes to promote adaptations in sprint performance, while still acknowledging that aerobic capacity improvements remain significant compared to other pitch shapes.

The variability of physical enjoyment, physiological responses, and technical-tactical performance according to the bout duration of small-sided games: a comparative study between female and male soccer players

BackgroundThis study aimed to compare various factors, namely perceived enjoyment (PE), percentage of peak heart rate (%HRpeak), blood lactate (La), rating of perceived exertion (RPE), and technical-tactical performance among soccer players across different bout durations (CB: continuous bout, MIB: medium intermittent bouts, and SIB: short intermittent bouts) and between male and female players during four-a-side (4vs4) small-sided games (SSGs) including goalkeepers.Methodssixteen female soccer players (age: 20.1 ± 0.5 years old) and sixteen professional male adults (age: 20.7 ± 0.7 years old) participated in the study. SSGs (4vs4) were performed in a CB: (1 × 12 min), and in an interval format: MIB: (2 × 6 min), and SIB: (3 × 4 min) with 2 min of passive recovery. PE was collected after each SSGs. The players’ heart rate (HR) was continuously measured, whereas ratings of perceived exertion (RPE) and, blood lactate concentration ([La]) were determined at the end of each SSGs. Technical-tactical performance were analyzed during each session of SSGs. Pitch dimensions were (length x width) (25 × 32 m), and relative space per players was 100 m2.ResultsFor female soccer players, medium intermittent bouts (MIB) elicited significantly higher perceived enjoyment (PE) compared to continuous bouts (CB) (p < 0.001) and short intermittent bouts (SIB) (p < 0.01). Conversely, for male soccer players, CB resulted in higher PE compared to MIB (p < 0.001) and SIB (p < 0.001). During CB and MIB, peak heart rate (PeakHR) and percentage of peak heart rate (%HRpeak) were significantly higher in female players compared to SIB (PeakHR: CB: p < 0.001; PeakHR: MIB: p < 0.01; %HRpeak: CB: p < 0.001; %HRpeak: MIB: p < 0.01). Blood lactate (La) and rating of perceived exertion (RPE) were significantly greater in CB compared to MIB (La: p < 0.001; RPE: p < 0.01) and SIB (La: p < 0.001; RPE: p < 0.001) for female players only. For male players, CB resulted in significantly higher PeakHR, %HRpeak, La, and RPE compared to MIB (peak HR: p < 0.01, dunb = 1.35; %HR: p < 0.01; La: p < 0.01; RPE: p < 0.01) and SIB (peak HR: p < 0,01; %HR: p < 0.01; RPE: md = 0.87, p < 0.05). Regarding technical-tactical performance, in female players, the % of successful passes, successful tackles, and successful duels were higher during SIB compared to CB (p < 0.01; p < 0.001; p < 0.001) and MIB compared to CB (p < 0.01; p < 0.001; p < 0.001), while ball loss was lower during SIB compared to CB (p < 0.001) and MIB compared to CB (p < 0.001). In male players, % of successful passes and tackles were higher during CB compared to MIB (p < 0.001 and p < 0.05) and SIB (p < 0.001 and p < 0.05), while CB had a lower % of ball loss compared to MIB (p < 0.01) and SIB (p < 0.001). There was no significant difference in the % of successful duels between the bouts for either gender.ConclusionThis study showed a difference in physical enjoyment between male and female soccer players depending on the bout duration of SSGs. For that, trainers should consider intermittent bouts for female soccer players and continuous bouts for male soccer players when designing SSGs-based training in order to significantly improve PE, training load, and technical-tactical performance.

Effect of bias potential and dimension on electrochemical migration of capacitors for implantable devices

Dendrite formation induced by electrochemical migration (ECM) is a common reliability problem occurring on printed circuit boards (PCBs), which significantly threatens the long-term safe operations of current implantable electronic devices (IEDs). Although several factors (i.e., contaminations, humidity, temperature) are proved to be the parameters closely related to ECM susceptibility of capacitors on a PCB under climate environments, further targeted research under other environments still needs to be conducted as ECM is highly environmental-dependent. Herein, the effects of bias potential and pitch dimension on ECM sensitivity are systematically studied using various sizes of capacitors on a test PCB under a human implantation environment. The finite element method first proves that a DC voltage pattern could be regarded as an accelerated test compared to other waveforms. Subsequent chronoamperometry tests using the DC potential further indicate that dendrite formation is closely related to pitch dimension under low bias potential, while under high bias potential electric field is also the dominating factor of dendrite formation for capacitors on a PCB. Benefiting from the electrochemical impedance spectroscopy (EIS) technique, the capacitor reliability under different corrosion states is also evaluated in a detailed manner. This work offers great value both in electronic corrosion mechanisms and future rational design for reliable IEDs.

Exploring the Impact and Innovative Application of Piano Art Instruction in the Context of Deep Learning

Abstract Social progress and technological development have brought sweeping changes to the field of art education. The innovative development of piano art instruction, as a part of art education, has a significant impact on students and the academic world. The study proposes a deep learning-based model for piano art instruction, taking into account the current state of piano art instruction, and investigates the impact of this model on students’ piano playing skills and appreciation of music art. The experimental group’s students improved their playing skills in the eight dimensions of fingering, timbre, pitch, rhythm, musical expression, emotional output, body language, and stage image. Except for timbre and stage image, the p-values of the experimental group and the control group in the other six dimensions of piano playing skills were less than 0.05, which effectively improved. In terms of music art appreciation, the total number of excellences in the three dimensions of aesthetic perception, artistic performance, and cultural understanding was 118, 131, and 126, respectively, and the total number of excellences in the experimental group was 32, 45, and 39. Obviously, piano art instruction based on deep learning has a positive impact on the students’ piano-playing skills and ability to appreciate music art.

A Study of the Aesthetic Application of Machine Learning to Five Education in Classical Music Interpretation

Abstract With the application of machine learning to the teaching of classical music in the context of five education as the research objective, this study first tested the feature extraction performance and classification of classical music with specific classical music data. Secondly, it explored the changes in the three elements of song aesthetics before and after machine learning five-education music teaching in two academic periods and analyzed the teaching effect it had on the task completion time and rhythmic accuracy of the songs. The use of audio analysis software in terms of task completion time, rhythmic accuracy, and pitch accuracy dimensions produces quantitative teaching effect ratings. The results show that the method in this paper obtains ideal classical music classification and feature extraction results and the ratings of the music feature extraction algorithms are in line with the real level of teachers and students. The experimental group and the control group, after teaching music using machine learning, took a similar time to learn the task, but the difference in rhythmic accuracy was large. The highest IOI value of the experimental group is only 0.07439, and the overall average of the group’s satisfaction with the teaching effect has increased by 0.842. This paper’s method is conducive to the development and innovation of music teaching.

Effect of offset on the precision of 3D-printed orthognathic surgical splints.

This study evaluated the effect of offset on the precision of three-dimensional (3D)-printed splints, proposing to optimize the splint design to compensate for systematic errors. 14 resin model sets were scanned and offset as a whole by given distances (0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, and 0.40mm). Intermediate splints (ISs) and final splints (FSs) were generated from the non-offset and offset models and grouped correspondingly, named as splint type-offset value, IS-0.05, for instance. Dentitions occluded with the splint were scanned. Translational and rotational deviations of the lower dentition relative to the upper dentition were 3D measured. Deviations of ISs and FSs were more evident in the vertical and pitch dimensions, and were mostly acceptable in other dimensions. ISs with offset ≥ 0.05mm showed vertical deviations significantly below 1mm (P < 0.05) while ISs with 0.10- to 0.30-mm offsets had pitch rotations significantly lower than 1° (P < 0.05). The Pitch of IS-0.35 was significantly larger than ISs with 0.15- to 0.30-mm offsets (P < 0.05). Meanwhile, FSs fit better as the offset increased and FSs with offsets ≥ 0.15mm all had deviations significantly lower than 1mm (for translation) or 1° (for rotation) (P < 0.05). Offset affects the precision of 3D-printed splints. Moderate offset values of 0.10 to 0.30mm are recommendable for ISs. Offset values ≥ 0.15mm are recommended for FSs in cases with stable final occlusion. This study found the optimal offset ranges for 3D-printed ISs and FSs via a standardized protocol.

Match running performance profiles of amputee football players at the national level

Even though running performance and positional profiles in football are well described, amputee football (AF) has different characteristics of the movement, pitch dimensions, and time played. There is a gap in the scientific literature about positional profiles based on running performance in AF. This study aimed to investigate the differences between positions, the influence of the amputation level or defect of the lower limb (LD), the differences in running performance between halves, and the relationship with the final match result. Thirteen AF National Team players were monitored by Global Navigation Satellite System (GNSS), tracking 24 official international matches for 17 months. Values of top speed, peak acceleration, peak deceleration, average distance per minute, sprint mean speed, GPS load per minute, inertial load per minute (Gs load/min), number of sprints per minute, and a number of impacts per minute were analyzed for defenders (DEF), midfielders (MID) and forwards (FOR). Additional factors analyzed were amputation level (below the knee, low amputation—LA or over the knee, high amputation—HA or defect of the lower limb—LD) and the match's final result. Midfielders had significantly higher running performance parameters compared to other positions (greater top speed than DEF (+ 0.3 m/s; p < 0.001) and FOR (+ 0.2 m/s; p = 0.045), greater peak acceleration and deceleration than DEF (+ 0.5 m/s2 for both measures; p < 0.001) and FOR (+ 0.4 and + 0.3 m/s2; p < 0.001 and p = 0.036, respectively), greater GPS load/minute than DEF (+ 0.2 load/min; p = 0.001) and FOR (+ 0.3 load/min; p < 0.001), greater Gs load per minute than DEF (+ 2.7 load/min; p < 0.001) and FOR (+ 1.8 load/min; p < 0.001), greater number of impacts per minute than DEF (+ 0.2 n/min; p < 0.001) and FOR (+ 0.2 n/min; p < 0.001). Players with LD had significantly higher running performance than those with LA or HA. In the match's second half, a decrease in running performance was registered. The trend of running more when losing could be observed—AF players had higher running parameters in lost matches, but the differences were not statistically significant. Further research complied with contextual game analysis is needed to assess the running performance of AF players deeply.

Inducing and disrupting flow during music performance.

Flow is defined as a state of total absorption in an activity, involving focused attention, deep engagement, loss of self-conscious awareness, and self-perceived temporal distortion. Musical flow has been associated with enhanced performance, but the bulk of previous research has investigated flow mechanisms using self-report methodology. Thus, little is known about the precise musical features that may induce or disrupt flow. This work aims to consider the experience of flow from a music performance perspective in order to investigate these features and introduces a method of measuring flow in real time. In Study 1, musicians reviewed a self-selected video of themselves performing, noting first, where in the performance they recalled "losing themselves" in the music, and second, where their focused state was interrupted. Thematic analysis of participant flow experiences suggests temporal, dynamic, pitch and timbral dimensions associated with the induction and disruption of flow. In Study 2, musicians were brought into the lab and recorded while performing a self-selected musical composition. Next, participants were asked to estimate the duration of their performance, and to rewatch their recordings to mark those places in which they recalled "losing themselves in the moment." We found that the proportion of performance time spent in flow significantly correlated with self-reported flow intensity, providing an intrinsic measure of flow and confirming the validity of our method to capture flow states in music performance. We then analyzed the music scores and participants' performed melodies. The results showed that stepwise motion, repeated sequence, and a lack of disjunct motion are common to flow state entry points, whereas disjunct motion and syncopation are common to flow state exit points. Overall, such initial findings suggest directions that warrant future study and, altogether, they have implications regarding utilizing flow in music performance contexts.

Sequence Processing in Music Predicts Reading Skills in Young Readers: A Longitudinal Study

Musical abilities, both in the pitch and temporal dimension, have been shown to be positively associated with phonological awareness and reading abilities in both children and adults. There is increasing evidence that the relationship between music and language relies primarily on the temporal dimension, including both meter and rhythm. It remains unclear to what extent skill level in these temporal aspects of music may uniquely contribute to the prediction of reading outcomes. A longitudinal design was used to test a group-administered musical sequence transcription task (MSTT). This task was designed to preferentially engage sequence processing skills while controlling for fine-grained pitch discrimination and rhythm in terms of temporal grouping. Forty-five children, native speakers of Portuguese (Mage = 7.4 years), completed the MSTT and a cognitive-linguistic protocol that included visual and auditory working memory tasks, as well as phonological awareness and reading tasks in second grade. Participants then completed reading assessments in third and fifth grades. Longitudinal regression models showed that MSTT and phonological awareness had comparable power to predict reading. The MSTT showed an overall classification accuracy for identifying low-achievement readers in Grades 2, 3, and 5 that was analogous to a comprehensive model including core predictors of reading disability. In addition, MSTT was the variable with the highest loading and the most discriminatory indicator of a phonological factor. These findings carry implications for the role of temporal sequence processing in contributing to the relationship between music and language and the potential use of MSTT as a language-independent, time- and cost-effective tool for the early identification of children at risk of reading disability.

Fabrication of temperature-selective thermal radiation surfaces utilizing surface texturing

Solid surfaces emit electromagnetic (EM) radiation whose wavelength varies with the temperature. Herein, a functional heat sink was developed by creating a temperature-selective heat release surface that raises the radiation flow at a specific temperature. We fabricated periodic V-grooves on an aluminum surface with a pitch dimension in the micron range by micro-cutting (Structure I), and a submicron periodic microstructure on a flat surface using an ultrashort pulsed laser (Structure II). Then, we fabricated a hybrid structure (Structure III) by forming Structure II over Structure I to investigate the effect of the surface microstructure on the radiation performance. Structure I had a high emissivities at certain wavelengths, like blazed grating, due to the reflection of EM waves within the fabricated V-groove. Structure II was found to have an effect similar to holographic grating, and Structure III increased the emissivity of Structure I and shifted the peak emissivity toward higher wavelengths. The radiation flux measured from the sample surface at various temperatures revealed that an increase in the surface area and emissivity were effective in increasing radiation. In particular, in Structure III, the radiation flux was significantly increased and varied with temperature. This indicates that the formation of a finer concavo-convex structure on a periodic structure could enable finer temperature selectivity for emitted radiation.

The Influence of Pitch Dimensions during Small-Sided Games to Reach Match Physical and Physiological Demands on the Youth Soccer Players.

The aims of this study were to (i) analyze the physical and physiological responses of four matches competition and (ii) to investigate the relationships among three different pitch dimensions of small-sided game (SSG) on the youth soccer players. Fifteen male U19 soccer players (age 17.3 ± 0.5 years, height 175.7 ± 5.6 cm, weight 68.5 ± 8.6 kg, playing experience 7.8 ± 1.4 years) were randomly assigned to three play areas: small (50 m2), medium (SSG-m, 150 m2) and large (SSG-l, 250 m2) area per player including goalkeeper. During the 4-week intervention, both groups performed three sets of 8 min with a passive rest period of 5 min between games. Differences in time-motion characteristics of players were measured with the Global Positioning System and assessed using a repeated measures ANOVA to compare the three game conditions and the magnitude-based inference to evaluate the pairwise comparison effects. The results showed that only the variables distance covered between 7.0-12.9 km·h-1 was not statistically significantly different among game conditions (p < 0.05; η = 0.21; small) and physiological response (i.e., hear rate of playing time spent 85-89% HRmax) also showed differences (p < 0.05; η = 0.25; small). The responses in SSG-m and SSG-l established them ass the format sizes ideal for replicating the physical responses during match competition. These findings could provide relevant information for coaches for use adequate pitch size (areas of 150 m2 and 250 m2) to reach the match-play scenarios found in match competition.

Physiological responses of small-sided vs. regular games in youth volleyball players

The aim of the present study was to evaluate the effects of two different formats of small-sided games (SSGs; 2 vs. 2 and 3 vs. 3) on physiological parameters in youth volleyball players. Twelve youth volleyball players (17.2 ± 7.44 years, 1.89 ± 0.6 m, 72.83 ± 8.57 kg) completed three different games formats (regular game (RG): 6 vs. 6, SSG3: 3 vs. 3 and SSG2: 2 vs. 2). associated with two pitch dimensions (i.e., 2 vs. 2 and 3 vs. 3 on 18 × 4.5 m; 6 vs. 6 on 18 × 9 m). Each player performed 4 × 5 min SSG with a recovery period of 1 min between bouts. All players were members of the same youth team and played in a professional league. They had at least 6 years of volleyball training and no current injuries. This study was carried out during the competitive period. Heart rate (HR), blood lactate ([La-]), and rating of perceived exertion (RPE) were measured. Compared to RG, physiological (i.e., HR and [La-]) and RPE responses were significantly higher during SSG3 and SSG2 (all p < 0.05; ƞp 2 = 0.77, ƞp 2 = 0.65, ƞp 2 = 0.30, respectively). Moreover, HR and RPE were significantly higher in SSG2 compared to SSG3. In contrast, no significant differences were observed in [La-] between SSG2 and SSG3. These results suggest that the number of players influences the exercise intensity in small-sided volleyball games in youth players. Therefore, coaches could benefit from incorporating SSGs to manipulate the exercise intensity in youth volleyball players.

A comparative surface evaluation of orthodontic mini-implants before and after en masse retraction-A SEM study.

To evaluate the changes in surface morphology of two different types of mini-implants after clinical en masse retraction using scanning electron microscopy. Fifty mini-implants of Dentos (Korea, Absoanchor, BH-1817-08) and Orlus (Korea, Yesanchor, C-1817) were inserted in patients in a split-mouth design who required en masse anterior retraction and absolute anchorage. Surface characteristics of mini-implants such as pitch (distance between consecutive threads), flank width (distance between root and crest), and taper were studied using scanning electron microscope (FEI nanosem450) before and after clinical use. Statistically significant difference (p value = 0.003) was found in a mean reduction of pitch dimension among the two groups with a mean difference of 25.000 μm. Also, a statistically significant difference was noted (p value = 0.001) in a mean reduction of flank width among Dentos implants as compared to Orlus implants. A statistically significant difference (p = 0.001) was seen in the mean reduction of taper dimension among Dentos group (0.0140 ± 0.02271) as compared to the Orlus group (0.0810 ± 0.05152). A marked reduction in surface morphology such as the pitch, flank width, and taper of both mini-implants after retrieval was observed. Dentos group of mini-implants displayed better dimensional stability post-retrieval as compared to the Orlus group of mini-implants. All the mini-screws showed milling defects in form of scratches on observation under scanning electron microscopy despite a smooth appearance to the naked eye.

When Chirophotonic Film Meets Wrinkles: Viewing Angle Independent Corrugated Photonic Crystal Paper.

Light manipulation strategies of nature have fascinated humans for centuries. In particular, structural colors are of considerable interest due to their ability to control the interaction between light and matter. Here, wrinkled photonic crystal papers (PCPs) are fabricated to demonstrate the consistent reflection of colors regardless of viewing angles. The nanoscale molecular self-assembly of a cholesteric liquid crystal (CLC) with a microscale corrugated surface is combined. Fully polymerizable CLC paints are uniaxially coated onto a wrinkled interpenetrating polymer network (IPN) substrate. Photopolymerization of the helicoidal nanostructures results in a flexible and free-standing PCP. The facile method of fabricating the wrinkled PCPs provides a scalable route for the development of novel chirophotonic materials with precisely controlled helical pitch and curvature dimensions. The reflection notch position of the flat PCP shifts to a lower wavelength when the viewing angle increased, while the selective reflection wavelength of wrinkled PCP is remained consistent regardless of viewing angles. The optical reflection of the 1D stripe-wrinkled PCP is dependent on the wrinkle direction. PCPs with different corrugated directions can be patterned to reduce the angular-dependent optical reflection of wrinkles. Furthermore, 2D wavy-wrinkled PCP is successfully developed that exhibit directionally independent reflection of color.

Performance analysis of professional U-23 portuguese players in small-sided games

The aim of this study was to examine the influence of different small-sided games (SSGs) format on external, internal load and technical actions of professional U-23 portuguese soccer players. Eight players (20.1±0.8 years, 180.4±7.2 cm, 75.9±4.9 kg) performed three different 4 vs. 4 ball possession SSGs (3x3 min play/rest) in different pitch dimensions, SSG1 16x24 m, SSG2 20x30 m and SSG3 24x36 m. All SSGs were video recorded for technical actions analysis. WIMU PROTM (RealTrack Systems, Almeria, Spain) inertial devices were used for internal and external load data collection. The distribution normality was determined with the Shapiro-Wilk test. Parametric and nonparametric statistics were selected accordingly. Statistical Package for the Social Sciences (SPSS™ 25.0 version) was used for data analysis. No significant differences were observed comparing the different SSGs in total distance covered, acceleration/deceleration distance, as well as in maximal and mean heart rate. Regarding the technical actions, no significant differences were observed in successful passes, contrary to the observed from SSG1 to SSG3 in duels (7.00±2.13; 4.38±2.44; 4.25±1.98), number of balls lost (2.63±1.30; 1.00±0.53; 0.88±1.12) and in between SSGs in high-speed running (p&lt;0.05, ES=0.37). In senior and professional soccer players, the modification of the pitch size between 16x24 m and 24x36 m during 4 vs. 4 ball possession SSGs with 3x3 min play/rest promotes modifications in the dynamic of technical actions and internal and external training load variables Keywords: Small-sided games, Professional soccer, Technical actions, External and internal load, Performance.

Heat transfer optimization in a horizontal helical-shaped ground heat exchanger through response surface methodology

Various combinations of objective functions and design variables have been considered in several optimization studies of ground heat exchangers (GHEs). In this study, the optimum values of the coil pitch and coil diameter of a helical-shaped GHE were determined to maximize its convection heat transfer rate. Central composite design was used to determine the coil pitch and coil diameter dimensions to be used in GHE modeling. Nine models were generated in Fusion360 which were then exported to ANSYS Fluent for CFD simulation. Then, a second-order model of the convective heat transfer rate per unit length as a function of the coil pitch and coil diameter was generated using the response surface methodology. For the design space considered (coil pitch: 600 to 1200 mm; coil diameter: 600 to 1200mm), the highest heat transfer rate was achieved at a coil diameter of 600mm and at a coil pitch of 1200mm. Furthermore, this study showed that if both the coil pitch and coil diameter are considered simultaneously in the optimization of the heat transfer rate of a helical-shaped GHE, then coil pitch would have a directly proportional relationship with the heat transfer rate, while coil diameter would have an inversely proportional relationship.

Optimal design of q ‐axis field winding structure of dual‐excited synchronous condenser

The dual-excited synchronous condenser (DESC) has two field windings whose axes are located at direct and quadrature axes respectively. The DESC has more capacity of absorbing reactive power than that of the traditional synchronous condenser (TSC). However, the q-axis field winding distributed on the d-axis magnetic pole surface can decrease the magnetic circuit area of the rotor core of DESC, thus it may result in the increase of the total harmonic distortion (THD) of the magnetic field and the oversaturation of the rotor magnetic circuit. In order to obtain better electromagnetic characteristics of DESC, a q-axis field winding structure is proposed by optimising the number of slots, slot pitch and slot dimensions. The influences of the number and pitch of slot in q-axis on the air-gap radial flux density and THD of DESC are studied under the d-, q- and dual-axis excitation modes. The dimensions of the q-axis slots are optimised by combining the time-stepping finite element method and Taguchi method, and the optimal structure of q-axis field winding is obtained. A 10-kVar DESC is developed to verify the simulation results. This study provides theoretical basis for the design and manufacture of the DESC.

High-Density Patterning of InGaZnO by CH4: a Comparative Study of RIE and Pulsed Plasma ALE.

InGaZnO (IGZO)-based thin-film transistors and selector diodes are increasingly investigated for a broad range of applications such as high-resolution displays, high-density memories, and high-speed computing. However, its potential to be a key material for next-generation devices is strongly contingent on developing patterning processes with minimal damage at nanoscale dimensions. IGZO can be etched using CH4-based plasma. Although the etched by-products are volatile, there remains a concern that passivation─an associated effect arising from the use of a hydrocarbon etchant─may inhibit the patterning process. However, there has been limited discussion on the CH4-based etching of IGZO and the subsequent patterning challenges arising with pitch scaling (<200 nm). In this work, we systematically investigate dry chemical etching schemes to pattern an IGZO film into densely packed nanostructures using CH4. Straight IGZO lines, ∼45 nm in width at a pitch of ∼135 nm, are produced by employing the traditional reactive ion etching method. While the passivating effect of CH4 does not impede the etching process, any further shrinkage of feature and pitch dimensions amplifies reactive ion etching-induced damage in the form of profile distortion and residue redeposition. We show that this is efficiently addressed via atomic layer etching (ALE) of IGZO with CH4 using a pulsed plasma. The unique combination of ALE and plasma pulsing enables controlled reduction of ion-assisted sputtering and redeposition of residues on the patterned IGZO features. This approach is highly scalable and is successfully applied here to achieve well-separated IGZO lines, with critical dimensions down to ∼20 nm at a dense pitch of ∼36 nm. These lines exhibit steep profiles (∼80°) and no undesirable change in IGZO composition post-patterning. Finally, ALE of IGZO under pulsed plasma, reproduced on 300 mm wafers, highlights its suitability in large-scale manufacturing for the intended applications.