Total Ground Research Articles

A LiDAR‐driven pruning algorithm to delineate canopy drainage areas of stemflow and throughfall drip points

Abstract Precipitation channelled down tree stems (stemflow) or into drip points of ‘throughfall’ beneath trees results in spatially concentrated inputs of water and chemicals to the ground. Currently, these flows are poorly characterised due to uncertainties about which branches redirect rainfall to stemflow or throughfall drip points. We introduce a graph theoretic algorithm that ‘prunes’ quantitative structural models of trees (derived from terrestrial LiDAR) to identify branches contributing to stemflow and those contributing to throughfall drip points. To demonstrate the method's utility, we analysed two trees with similar canopy sizes but contrasting canopy architecture and rainfall partitioning behaviours. For both trees, the branch ‘watershed’ area contributing to stemflow (under conditions assumed to represent moderate precipitation intensity) was found to be only half of the total ground area covered by the canopy. The study also revealed significant variations between trees in the number and median contribution areas of modelled throughfall drip points (69 vs. 94 drip points tree−1, with contributing projected areas of 28.6 vs. 7.8 m2 tree−1, respectively). Branch diameter, surface area, volumes and woody area index of components contributing to stemflow and throughfall drip points may play a role in the trees' differing rainfall partitioning behaviours. Our pruning algorithm, enabled by the proliferation of LiDAR observations of canopy structure, promises to enhance studies of canopy hydrology. It offers a novel approach to refine our understanding of how trees interact with rainfall, thereby broadening the utility of existing LiDAR data in environmental research.

Investigation of spin polarized semiconductor Cs2XMoBr6 (X = Li, Na) compounds for spintronic and optoelectronic applications

This study has applied the density functional theory (DFT) to calculate the structural, magnetoelectronic, optical, and thermoelectric characteristics of Cs2XMoBr6 (X = Li, Na). The magnetic stability of studied compounds is examined by minimizing their total ground state energies. Also, both compounds exhibit cubic stability by tolerance factor as well as negative enthalpy of formation. The analysis of spin-dependent electronic properties reveals the semiconductor nature of mentioned materials in both spin-up/dn versions. The computed Eg of 0.90/1.99 eV in spin-up/dn sections for Cs2NaMoBr6 while Cs2LiMoBr6 reveals Eg of 1.99/1.21 eV in spin-up/dn version. The optical properties show that incident light is optimally absorbed in visible to ultraviolet areas, indicating their potential use in UV-based photo sensors and other photovoltaic gadgets. The Mo-atom primarily participate to the total magnetic moment (μB(Tot)) for Cs2XMoBr6. Further, the material's high figure of merit (ZT) >0.7 within the 300 - 800 K temperature range for Cs2XMoBr6 indicate its high efficiency in thermoelectric (TE) applications. Semiconducting electronic bands with highly asymmetric spin polarization as well as greater TE efficiency, Cs2XMoBr6 materials are appropriate for uses in spintronics and energy harvesting.

Influence of the Beiring Sorenson Hold and the Barbell Back Squat on Running Cadence in Military Ruck Marching: A Cross-Sectional Observational Study

Ruck marching is a key performance indicator for tactical preparation; however, marching under load causes changes in biomechanics, which can increase injury risk. Although this risk of injury from changes is known, current methods commonly used for assessing physical fitness have not adequately identified how to minimize these changes. In this observational study, 14 ROTC cadets underwent a series of physical muscular fitness tests prior to performing a six-mile ruck march. These included an evaluation of postural endurance via the Biering Sorenson hold, lower body strength via the back squat, and upper body strength via bench press. After the tests were performed, ruck march performance was evaluated by total time to completion and running dynamics. Multiple regression analysis was performed to determine if bench press maximum, back squat maximum, or Sorenson hold were predictors of the performance of the ruck March. Average cadence shared a positive significant relationship with the Sorenson hold (r = 0.76, p = 0.02) and a negative significant relationship with the back squat (r = -0.76, p = 0.02). Additionally, the Sorenson hold did not share any significant relationships with total ruck time (r = -0.3, p = 0.29) or ground contact time (r = -0.41, p = 0.31). The back squat did not share significant relationships with ground contact time (r = -0.37, p = 0.37) or average smoothness (r = -0.38, p = 0.31). This study highlights the potential relationship that the Sorenson hold and back squat can have on running cadence, which has shown significant changes in previous research evaluating the changes in running performance and characteristics from weight ruck marching. Further investigation of the relationship of these assessments on the performance of ruck marching should be performed with larger numbers of cadets in the future.

Comparisons of ground reaction force between successful and unsuccessful lifts in snatch and clean-and-jerk in weightlifting

<p>目的：利用符合舉重運動特性的單軸測力平台，探討菁英選手在抓舉與挺舉時，成功與失敗地面反作用力參數之差異。方法：11名大專舉重選手為本研究參與者。參與者進行符合正式比賽規定的抓舉與挺舉動作時，雙腳需分別站立於長2公尺寬1公尺的舉重專用測力平台。每位參與者先完成抓舉再進行挺舉，每次試舉過程利用測力平台收集地面反作用力，並計算各階段力量峰值、發力率、壓力中心前後位移、雙腳寬度距離、右腳力量比例，再進行差異比較。結果：成功抓舉在第一拉期力量峰值、接槓時間顯著大於失敗；高比例的參與者，在接槓期力量峰值亦小於失敗。成功挺舉在上搏接槓期力量峰值顯著小於失敗。結論：失敗最高的階段發生在接槓期。抓舉應提高第一拉期的力量，以爭取更多接槓時間。接槓期應減少負荷力量；在上挺接槓分腿支撐時，可將槓鈴與壓力中心向後移動，並維持壓力中心接近於雙腳跨距中間偏前的位置。舉重專用測力平台能全程給予選手發力方式的回饋，有利於修正技術。</p> <p> </p><p>Purpose: To explore the differences in ground reaction force parameters between successful and unsuccessful lifts during the snatch and clean-and-jerk using an internally developed uniaxial force platform. Methods: Eleven elite college-level weightlifters were recruited in this study. They were asked to stand on a 2m1m force platform to perform the snatch and clean-and-jerk with self-selected weights by following the official competition rules. The maximal total ground reaction force (vGRF), rate of force development, the center of pressure, feet distance, and force distribution of the right foot were calculated and compared across different phases. Results: In the snatch, the peak vGRF of the first pull and the catching time in successful lifts were significantly higher than in unsuccessful ones. Moreover, the peak vGRF of catching in successful lifts was lower than in unsuccessful lifts. In successful clean-and-jerk, the peak vGRF of catching during clean in successful attempts was lower than in unsuccessful lifts. Conclusion: The phase with the highest failure rate occurred during the catch phase. In the snatch, increasing the force during the first pull may allow for more time in the catching phase. It is also recommended that the loading force should be reduced during the catching phase. In the split jerk, results showed moving the barbell and the center of pressure backward while maintaining the center of pressure slightly forward of the midpoint between the feet can improve stability. It is recommended that during weightlifting training, the internally developed force platform serves as a valuable tool to provide feedback on biomechanical indicators such as force development and help coaches and athletes refine weightlifting techniques in real-time.</p> <p> </p>

Whole-body linear momentum control in two-foot running jumps in male basketball players

Running jumps that depart the ground from two feet require momenta redirection upward from initial momenta that are primarily horizontal. It is not known how each leg generates backward and upward impulses from ground reaction forces to satisfy this mechanical objective when jumping to maximize height. We examined whole-body linear momentum control strategies during these two-foot running jumps by uncovering the roles of each leg in impulse generation. 3D motion capture and force plates were used to record 14 male basketball players performing two-foot running jumps towards an adjustable basketball hoop. Total ground contact phase started from the first leg ground contact and ended at takeoff and was divided into center of mass descent and ascent subphases. During the total ground contact phase, all participants generated significantly more upward impulse with the first leg and ten participants generated significantly more backward impulse with the first leg compared to the second leg. During the descent subphase, all participants generated significantly more upward and backward impulses with the first leg. During the ascent subphase, all but one participant generated significantly more backward impulse with the second leg. In addition to group-level statistics, participant-specific strategies were described. Overall, this study revealed the fundamental whole-body momentum control strategies used in two-foot running jumps and supports future research into optimal jump techniques and training interventions that respect the need to satisfy the mechanical objectives of the movement.

Production of maps for bearing capacity of the shallow foundation in Baghdad city using SPTs and MATLAB software

Abstract The standard penetration tests are considered one of the most important tests to determine the bearing capacity of the soil. In this research, a set of objective maps and equations were produced to estimate the bearing capacity of shallow foundations based on the results of SPTs conducted in Baghdad Governorate. The work includes drilling 213 wells 10 meters deep below the surface of the earth, and conducting three standard penetration tests (SPT) on each well at depths of 1.5, 6 and 9 m. The bearing capacity of the shallow foundations in the city of Baghdad was determined using the MATLAB program after the SPT values were corrected. Then several polynomial equations with multi-order interpolation are proposed to estimate the bearing capacity of the foundation, but the first-order polynomial equation is considered simpler and straightforward. Moreover, the root mean square error (RMSE) of all the proposed polynomial equations is almost the same. Thematic maps show the difference in the carrying capacity of shallow foundations across the total ground of Baghdad Governorate with respect to different depths. Then, a comparison was made between the calculated and estimated values of the foundation’s bearing capacity, where the results showed a discrepancy of 30% at a confidence level of 95%.

Increased winter‐killed cover crop seeding rate may not increase soil health outcomes

AbstractImplementing soil conservation practices can begin to restore degraded soils, improve soil health, and increase overall ecosystem services. Cover cropping is an effective strategy to rebuild soil quality through decreased erosion and increased residue inputs, which can help build soil organic matter. Cover crop seeding rate may have a positive relationship with ecosystem services; however, it is unknown whether this is realized at or below the recommended cover crop seeding rate. The goal of this study was to identify the relationship between cover crop seeding rate and soil health biogeochemical measures across the growing season using five oat (Avena sativa L.)–pea (Pisum sativum L.) cover crop treatments of 0%, 25%, 50%, 75%, and 100% the industry standard seeding rate at the University of Massachusetts Amherst Research Farm. Soils were tested for soil carbon (C), nitrogen (N), and microbial measures at winter kill, spring thaw, post‐planting, and succeeding cash crop harvest. Soil measures did not vary among seeding rates, but total ground cover was consistent among treatments due to weed growth. Soil health measures vary seasonally reflecting soil microbial activity. Our study provides initial evidence that soil biogeochemical responses do not respond to increased seeding rate within one growing season when the resulting groundcover—cover crop biomass plus weeds—is consistent across seeding rates, but sampling date can influence the magnitude of soil biological and chemical soil health metrics.

A Comprehensive Comparison of Photogrammetric and RTK-GPS Methods for General Order Land Surveying

One of the main objectives of modern-day surveying is to maximize the efficiency and accuracy of mapping a landscape for natural features and elevations prior to the start of a construction project. This paper focuses on a comparison between terrestrial and aerial photogrammetry and real-time kinematic global positioning systems (RTK-GPSs) in terms of elevation accuracy, data expenditure, and time for each survey to be completed. Two sites in San Diego County were chosen to be studied with a combined area of about 1.14 acres, and a total station system was used to establish 572 control points between both areas. Two of the three methods investigated produced similar results in elevation and were well within the established standard, as the terrestrial photogrammetry averaged 0.0583 feet of error, the aerial photogrammetry averaged 0.345 feet of error, and the RTK-GPS averaged 0.0432 feet of error when compared to the total station ground truth. If data consumption is not a concern, the terrestrial photogrammetric method should be preferred to the aerial photogrammetric and RTK-GPS methods in topographic mapping and land monitoring due to the increase in time efficiency and in surface model detail while keeping within the Caltrans specified tolerance of error of 0.2 feet. For general order land surveys, the photogrammetric approach utilized with a Looq scanner would provide the most efficient and cost-effective survey while staying within the 0.2 foot tolerance of error. This method also allows for the utmost clarity of the resulting point cloud when analyzing terrain, break lines, or other features in the survey area.

Do lower limb kinetic and kinematic differences in drop jump landings persist when players have returned to sport following knee ligamentous injuries?

Knee injuries (KI) are identified as one of the most burdensome lower limb injuries in football with long and complicated rehabilitation and high re-injury risk. Current research often describes technique deficits being present upon RTS, often being a result of poor return to sport (RTS) testing procedures. More recently, research has advocated the use of single leg vertical jump assessments, due to the specificity of the movement to injury mechanisms and the ability to consider different phases of the task to inform practitioners of joint contributions to the propulsion and landing phases. The aim of this research is to identify whether these functional deficits exist 12-24 months post RTS authorisation, to help inform future RTS in applied practice. Twenty-four semi-professional male footballers (mean ± SD: age 25 ± 4 years; stature 182 ± 7 cm; body mass 80 ± 8 kg) were recruited into a previously injured and a control group. Participants completed 5 repetitions of single leg drop jump (SLDJ). Jump height, ground contact time, reactive strength index, peak moments, angles and power contributions for the hip, knee and ankle were measured using Qualisys Track Manager then exported to Visual 3D. This study was approved by the Edge Hill University Ethics Committee. No significant findings were identified for landing one however, during the propulsion phase there was a difference between groups (P = 0.026, d=1.14) for knee flexion at take-off. Most differences were identified during landing two bilaterally in both groups. Within the injured group, differences were identified for peak hip (P = 0.011, d = 0.028) and knee powers (P < 0.001, d = 1.269), hip (P < 0.001, d = 1.924) and knee power contribution % (P < 0.001, d = 1.269). No differences were identified for the performance measures or through performing statistical parametric mapping for hip and knee powers for all three phases. Joint coupling analysis was conducted for the total ground contact time amalgamating the landing and propulsion phase, this was analysed as Hip-Knee, Hip-Ankle and Knee-Ankle, with significant findings in Hip-Knee and Hip-ankle. Both groups elicited bilateral differences however, no differences between the injured limb and dominant control limb were identified. To better apply this form of analysis to RTS testing, functional movements such should be undertaken when athletes are injury free to provide baseline measurements to refer to if undertaking rehabilitation from KI. Likewise, the current study identified that joint contributions could be identified in a more applied setting using the range of motion data from each joint.

Contribution of VLF electromagnetic survey to the investigation of Hessdalen lights (Norway)

Hessdalen valley in Norway is known for luminous phenomena suddenly and evenly appearing temporarily. Since several decades, these phenomena are observed by many witnesses, and they are sometimes traced by geophysical devices. The first appearance in modern times was reported in 1981 but systematic observations started during winter of 1984 when the Hessdalen project was launched. Later, Østfold University College led the project and yearly organized one to two field campaigns, with the objective to systematically record and investigate the phenomenon. Till that epoch, detailed tectonics, fault systems and superficial conductive structures remained unknown. Therefore, during the last years, VLF surveys have been performed in Hessdalen valley as part of six geophysical field campaigns which sometimes also included Total Magnetic Field and Self Potential spatial ground measurements. VLF measurements have been carried out on a 20 m average spacing along many traces totaling to100 km length. The entire covered area was about 100 km2.In this paper, we focus on the results of the VLF measurements. Several conductive zones have been found. They are mainly related to mineral deposits (mainly sulfides). The trace at the ground surface of these conductive zones could suggest that they draw an ellipse of 6 by12 km, related to the shape of the gabbro intrusion present in the area and oriented in the SW-NE direction. The results combined with other geophysical data contribute to better understand how the near surface structures (depth less than a few hundred meters) could supply the generation of the so-called Hessdalen lights (‘HL’) and explain why these lights appear inside this valley. The particular geological structure detected in Hessdalen valley may encourage similar campaigns in other areas where similar phenomena are observed.

Increased global cropland greening as a response to the unusual reduction in atmospheric PM₂.₅ concentrations during the COVID-19 lockdown period

The devastating effects of COVID-19 pandemic have widely affected human lives and economy across the globe. There were significant changes in the global environmental conditions in response to the lockdown (LD) restrictions made due to COVID-19. The direct impact of LD on environment is analysed widely across the latitudes, but its secondary effect remains largely unexplored. Therefore, we examine the changes in particulate matter (PM₂.₅) during LD, and its impact on the global croplands. Our analysis finds that there is a substantial decline in the global PM₂.₅ concentrations during LD (2020) compared to pre-lockdown (PreLD: 2017–2019) in India (10–20%), East China (EC, 10%), Western Europe (WE, 10%) and Nigeria (10%), which are also the cropland dominated regions. Partial correlation analysis reveals that the decline in PM₂.₅ positively affects the cropland greening when the influence of temperature, precipitation and soil moisture are limited. Croplands in India, EC, Nigeria and WE became more greener as a result of the improvement in air quality by the reduction in particulates such as PM₂.₅ during LD, with an increase in the Enhanced Vegetation Index (EVI) of about 0.05–0.1, 0.05, 0.05 and 0.05–0.1, respectively. As a result of cropland greening, increase in the total above ground biomass production (TAGP) and crop yield (TWSO) is also found in EC, India and Europe. In addition, the improvement in PM₂.₅ pollution and associated changes in meteorology also influenced the cropland phenology, where the crop development stage has prolonged in India for wet-rice (1–20%) and maize (1–10%). Therefore, this study sheds light on the response of global croplands to LD-induced improvements in PM₂.₅ pollution. These finding have implications for addressing issues of air pollution, global warming, climate change, environmental conservation and food security to achieve the Sustainable Development Goals (SDGs).

Higher Values of Force and Acceleration in Rear Cross Than Lead Jab: Differences in Technique Execution by Boxers

Background: Boxing, a globally popular combat sport, demands technical precision and powerful strikes at the same time. The kinetic assessment of straight punches, specifically the rear cross and lead jab, is crucial for understanding the biomechanical factors influencing punch effectiveness. This study aims to explore the kinetic properties of these punches in trained boxers, focusing on punch force, acceleration, and the concept of a proximal-to-distal pattern. Methods: Thirteen advanced-level male boxers (body weight 90.6 ± 19.2 kg, height 184.0 ± 7.4 cm, experience 9.5 ± 6.5 y) from local clubs participated in this study. Using a force plate and wireless IMU sensors, we recorded punch force and limb acceleration during the execution of rear-cross and lead-jab punches. Data analysis involved statistical tests to compare the kinetic differences (Mann–Whitney U-test) between the two punch types and assessment of the influence of body mass and training tenure on punch effectiveness (multiple regression analysis). Significant differences were observed between the rear cross and lead jab in terms of total ground reaction force (x¯ = 1709.28 N vs. x¯ = 1176.55 N), acceleration of the fist (x¯ = 94.33 m/s2 vs. x¯ = 66.07 m/s2), forearm (x¯ = 67.11 m/s2 vs. x¯ = 41.62 m/s2) and arm (x¯ = 88.40 m/s2 vs. x¯ = 81.36 m/s2), and target contact time (x¯ = 0.03 s vs. 0.02 s). The rear-cross punch exhibited higher kinetic values, indicating greater effectiveness. Additionally, body mass and training tenure were identified as significant factors influencing punch force (R2 score = 0.640). Conclusions: This study confirmed the biomechanical superiority of the rear cross over the lead jab in terms of generated force among trained boxers. The findings highlight the importance of coordination between each segment’s acceleration to generate a powerful strike. These insights are valuable for coaches and athletes in optimizing training strategies for boxing.

Uncoupled thermo-hydro-mechanical modeling of a pykrete diaphragm wall for an alternative artificial ground freezing application

El Harrach Center metro station is an actual project constructed with conventional diaphragm walls in Algiers. This article primarily consists of a parametric study that makes use of the station's geometry for comparative analysis. In this way, three gaps are investigated using an alternative artificial ground freezing (AGF) application. The impact of thermal conductivity, specific heat capacity, and thermal expansion on the diaphragm wall’s stability were examined; an innovative pykrete wall was investigated; and a new procedure was developed after modeling 216 cases of diaphragm walls with uncoupled thermo-hydro-mechanical modeling via the Plaxis program. In terms of total displacement, ground settlement, horizontal displacement, and excavation uplift, the diaphragm walls were different with and without thermal modeling by 96.20, 100.50, 4.20, and 2.50 mm, respectively. The effectiveness and stability of the innovative pykrete wall have been demonstrated to accurately represent on-site behaviour due to its perfect comportment against internal forces compared to other types of walls. The new procedure was developed regarding the optimum case that facilitates understanding the factors affecting the AGF method (distance between pipes, pipe diameter, freezing temperature, and freezing duration) according to its importance, cost, and the novel potential of thermal modeling for deep excavation projects.

MEMS highly sensitive and large-area force plate for total ground reaction force measurement of running ant

Terrestrial insects exhibit agile manoeuvrability while running. However, the ground reaction force (GRF) in small insects remains poorly understood owing to its size and acting force. Here, we present a force plate for the measurement of total GRF during the running motion of ants with a force on the order of several tens of μN. The proposed force plate consists of a sufficiently large plate for several step cycles and four supporting cantilevers with highly sensitive piezoresistive elements. The plate and sensor chips were fabricated separately and combined during postprocessing. Two sizes of force plates were designed and fabricated for a large ant (Camponotus japonicas) and small ant (Messor aciculatus) with force resolution less than 1 μN. The developed force plates were calibrated by applying vertical forces at 32 points on the plate. Using the fabricated force plate, we measured the total GRF over several step cycles as the ant ran along the plate. Consequently, it was suggested that the ant ran with small vibrations in the direction of gravity.

Correlations to estimate the ground loading from small scale propane BLEVE experiments

This paper presents small-scale propane BLEVE (Boiling Liquid Expanding Vapor Explosion) experiments coupled with an investigation into ground loading dynamics. The experiments utilized cylindrical aluminum pressure vessels, with a diameter of 50 mm and a length of 300 mm. The controlled variables included burst pressure, liquid fill level, and weakened length. Both high and low-speed measurements of internal pressure and ground force were conducted during the experiments. The dependent variables analyzed were peak total ground load, force duration, and impulse. The findings from the study show trends in ground force and impulse with alterations in failure pressure, fill level and weakened length. Specifically, ground force and impulse exhibit an upward trend with increasing failure pressure, fill level and weakened length (cut length). For the first time, comprehensive correlations have been developed, incorporating the controlled variables, as well as theoretical boiling wave speed and vapor speed, to estimate the dependent variables, which represents a significant contribution in the field. However, the study does acknowledge the presence of scatter in the data, which are believed to be associated with the intricacies of the vessel opening process. It should be noted that this correlation has not been validated for larger scales. Once validated on a larger scale, these correlations can be directly applied in the design and practice of civil infrastructure to enhance the structural integrity. Additionally, the research has direct implications for industrial applications, allowing for the quantitative assessment of risks associated with bridge collapse during the transportation of PLGs.

Yield and dry matter production of soybean response to late planting in southwestern Japan

ABSTRACT The selection of the sowing date is one of the most important decisions in soybean production. It is important for farmers to know the expected seed yield when developing a sowing plan. The objective of this study was to quantitatively reveal the decreased seed yield ratio during late sowing in southwestern Japan under irrigated conditions. Total above ground dry matter and distribution were measured from July to August sowing in 2018 and 2019 in Fukuyama, Hiroshima, Japan. The harvest index in the August sowing did not decrease compared to the July sowing under irrigated conditions. The decrease in yield was related to the total aboveground dry matter rather than to the harvest index. The decrease in total aboveground dry matter was related to the total amount of solar radiation intercepted rather than to radiation use efficiency. A significant regression equation was obtained for the relative yield, which was calculated from the maximum seed yield observed from early to mid-July. When seeds were sown after mid-July, our result showed that the seed yield will decrease by 0.60% per day for Sachiyutaka A1 and by 0.64% for Akimaro, even under conditions of 100% seedling establishment and controlled soil water conditions. This regression equation can be used in fields as an indicator of seed yield where irrigation is possible.

Exploring the multifaceted properties: electronic, magnetic, Curie temperature, elastic, thermal, and thermoelectric characteristics of gadolinium-filled PtSb3 skutterudite.

The investigation of binary and filled skutterudite structures, particularly PtSb3 and GdPt4Sb12, has gained significant attention, becoming a focal point in scientific research. This comprehensive report delves into the intrinsic characteristics of these structures using Density Functional Theory (DFT). Initially, we assess the structural stability of PtSb3 and GdPt4Sb12 by examining their total ground state energy and cohesive energy, employing the Brich Murnaghan equation of state to determine stability in various configurations. Further insights are gained by exploring second-order elastic constants (SOEC's) to extend our understanding of structural stability. The electronic structures are then meticulously defined through a quantum mechanical treatment, employing a combination of two distinct spin-polarized approximation schemes: Perdew-Burke-Ernzerhof Generalised Gradient Approximation (PBE-GGA) and Tran-Blaha modified Becke-Johnson (TB-mBJ). The resulting band structures reveal a symmetry in electronic behavior, showcasing spin-magnetic moments of 3 μB and 7.58 μB per formula unit, with the primary contributions emanating from the Pt 3d and Pt4+ 3d-transition elements. To gauge thermal stability, we evaluate the phonon-dependent Grüneisen parameter (γ) across specific temperature ranges. The study extends to exploring transport properties as a function of chemical potential (μ - EF) at various temperatures. The findings suggest that these designed materials hold substantial potential for diverse applications, particularly in conventional spin-based and thermoelectric technologies. The comprehensive insights obtained through this investigation pave the way for a deeper understanding and broader implications in various technological domains.

Maximizing plyometric training for adolescents: a meta-analysis of ground contact frequency and overall intervention time on jumping ability: a systematic review and meta-analysis

Plyometric training boosts adolescents' jumping ability, crucial for athletic success and health. However, the best total ground contact frequency (TGCF) and overall intervention time (OIT) for these exercises remain unclear. This meta-analysis aims to identify optimal TGCF and OIT in plyometric training for adolescents, focusing on countermovement jump (CMJ) and squat jump (SJ) outcomes. This systematic review encompassed five databases and included 38 studies with 50 randomized controlled experiments and 3347 participants. We used the Cochrane risk assessment tool for study quality and Review Manager 5.4 for data analysis. The current meta-analysis incorporated a total of 38 studies, comprising 50 sets of randomized controlled trials, to investigate the influence of different TGCFs and OITs on plyometric training. The Cochrane risk assessment tool indicated that all the included studies were classified as low risk. Various TGCFs in plyometric training positively affected CMJ and SJ heights in adolescents. The TGCF of less than 900 was ideal for enhancing CMJ, whereas more than 1400 was effective for SJ. The optimal OIT was 400–600 min, specifically, 500–600 min for CMJ and 400–500 min for SJ. Plyometric training improves jumping ability in adolescents. Lower ground contact frequency (< 900 contacts) enhances CMJ, while higher ground contact frequency (> 1400 contacts) is more effective for SJ. Optimal intervention time ranges from 400 to 600 min, with 500 to 600 min benefiting CMJ and 400 to 500 min improving SJ.

Offshore near-fault pulse-like ground motions: An insight into the DONET1 seafloor ground motions from the 2016 Mw6.0 Off-Mie earthquake in Japan

Offshore near-fault ground motions were obtained by the DONET1 seafloor seismic network during the 2016 Off-Mie Mw6.0 earthquake that occurred in the Nankai Trough of Japan. These data provide an opportunity for exploring the characteristics of offshore near-fault ground motions, especially pulse-like ground motions. A comparison of the offshore and onshore near-fault ground motions indicates that the recorded offshore spectral acceleration (SA) in the period of 0.5–5.0 s and peak ground velocity (PGV) for this earthquake are higher than those of the onshore values, and the observed maximum spectral value (βmax) of the offshore near-fault ground motions in this event is underestimated by the design spectra in the seismic codes of China, the United States, and Japan. Based on the Hilbert-Huang transform method, eight offshore pulse-like ground motion records are identified and extracted in the Off-Mie earthquake. The primary analysis indicates that the pulse-like ground motion may be caused by the directivity effect and the radiation pattern. Comparing the pulse parameters, time-frequency parameters, and response spectra of offshore and onshore pulse-like ground motions, the findings demonstrate that within the context of this earthquake event, approximately half of the offshore pulse amplitude (Vp) exceeds the predicted values of onshore models; the low-frequency components of offshore pulse-like ground motions of this event are more pronounced, constituting a larger portion of the total ground motion energy; offshore pulse-like ground motions exhibit a tendency to possess higher maximum instantaneous energy (Einst) compared to onshore pulse-like ground motions with similar rupture distances. Moreover, the βmax of offshore pulse-like ground motions is found to be greater than that of onshore pulse-like ground motions in medium to long periods (>0.5 s). The identified and characteristic recognition of offshore near fault pulse-like ground motion revealed by this earthquake event raises new concerns about seismic design for offshore engineering.

Shifts of the soil microbiome composition induced by plant–plant interactions under increasing cover crop densities and diversities

Interspecific and intraspecific competition and facilitation have been a focus of study in plant-plant interactions, but their influence on plant recruitment of soil microbes is unknown. In this greenhouse microcosm experiment, three cover crops (alfalfa, brassica, and fescue) were grown alone, in paired mixtures, and all together under different densities. For all monoculture trials, total pot biomass increased as density increased. Monoculture plantings of brassica were associated with the bacteria Azospirillum spp., fescue with Ensifer adhaerens, and alfalfa with both bacterial taxa. In the polycultures of cover crops, for all plant mixtures, total above-ground alfalfa biomass increased with density, and total above ground brassica biomass remained unchanged. For each plant mixture, differential abundances highlighted bacterial taxa which had not been previously identified in monocultures. For instance, mixtures of all three plants showed an increase in abundance of Planctomyces sp. SH-PL14 and Sandaracinus amylolyticus which were not represented in the monocultures. Facilitation was best supported for the alfalfa-fescue interaction as the total above ground biomass was the highest of any mixture. Additionally, the bulk soil microbiome that correlated with increasing plant densities showed increases in plant growth-promoting rhizobacteria such as Achromobacter xylosoxidans, Stentotrophomonas spp., and Azospirillum sp. In contrast, Agrobacterium tumefaciens, a previously known generalist phytopathogen, also increased with alfalfa-fescue plant densities. This could suggest a strategy by which, after facilitation, a plant neighbor could culture a pathogen that could be more detrimental to the other.