Search Results (5,425)

In high-concentration tailings backfilling, the stability of the backfill largely depends on the slurry’s self-weighted siltation behavior. Red mud—the strongly alkaline by-product of the Bayer process and a mixture of coarse and fine particles—requires a clear understanding of its self-weight settling–consolidation mechanisms to ensure safe and efficient backfilling. In this study, red mud slurry was selected as the research object, and a multi-scale approach combining sedimentation column tests and microstructural image analysis was employed to reveal the intrinsic relationships among the sediment layer height, sedimentation rate, and pore structure changes during self-weighted siltation. The results show that the flocculated structure of red mud slurry exhibits distinct stratification during self-weighted siltation, including a clarified layer, a structural transition layer, and a dense sediment layer. During the siltation process, the sediment layer height, sedimentation rate, and floc structure of red mud evolve nonlinearly. The addition of flocculants significantly enhances the formation rate of flocculated structures but increases the porosity of the sediment body. At the macroscopic level, this results in a shortened self-weighted siltation time and increased final sediment layer height. To describe the regulatory effect of flocculants on red mud floc structure, a macro–micro predictive model for the sediment layer height was established by introducing a structural enhancement coefficient, considering the effect of flocculants. The model achieved a prediction error within 16%. These findings provide theoretical support for structural control technologies and process optimization of high-concentration fine tailings backfilling, thereby contributing to the sustainable utilization of red mud and the development of environmentally responsible backfilling practices. Full article

State-of-the-art geotechnical and structural analyses commonly rely on finite-element analysis, treating soil and structure models separately. Incorporating the overall stiffness of the structure into the geotechnical model enables more realistic settlement predictions and assessments of founding force distribution, ensuring optimized and cost-effective designs. Although stiffness increases with building height, the effective contribution to settlement control is limited to a finite number of floors, making the internal stiffness distribution more relevant than the construction method itself. Reliable predictions require modeling approaches that realistically represent structural stiffness. This study evaluates various equivalent-model techniques in PLAXIS 3D and SOFiSTiK for their practicability and accuracy and explains their application. While simplified methods can adequately capture total stiffness under uniform distribution, constructing a full 3D model may be faster or more practical than elaborate simplifications requiring extensive setup and post-processing. Moreover, the construction sequence and evolving stiffness during the build, as well as time-dependent effects like creep and limit-state-dependent stiffness changes within structural elements, significantly influence settlements. A 3D structural model allows these factors to be accounted for comprehensively. Therefore, whenever feasible, geotechnical settlement analyses should employ full 3D structural models. Full article

Background/Objectives: Cast walkers (CWs) are often prescribed to offload diabetic foot ulcers (DFUs). However, their mass, the degree of ankle immobilization and the limb length discrepancy they induce may increase the energetic demands of walking, contributing to lower adherence and poorer healing. The purpose of this study was to evaluate the effects of different commercially available CW options on the metabolic costs and perceived exertion of walking, and on related spatiotemporal kinematics, in healthy young participants as an initial step to understanding factors that impact adherence in patients with DFUs. Methods: Participants walked on an instrumented treadmill at a standardized speed for six minutes under five footwear conditions: (1) athletic shoes only (control); (2) ankle-high CW on the dominant limb with athletic shoe on the contralateral limb; (3) condition two with an external lift on the athletic shoe; (4 and 5) conditions two and three with a knee-high CW. Condition 1 was performed first, after which the CW conditions were randomized. During all conditions, a portable calorimeter recorded gas exchange on a breath-by-breath basis. The metabolic cost of transport (MCoT) was quantified as the mean oxygen consumed per meter walked per kilogram body mass, after accounting for standing. After walking, participants reported perceived exertion using the Borg Rating of Perceived Exertion scale (RPE). From the treadmill data, we extracted the mean step width (SW) as well as absolute values for symmetry indices (SIs) for step length (SL) and step time (ST), all of which have associations with MCoT. For each outcome, linear mixed models compared each CW condition with the control and tested for effects of CW height (ankle-high vs. knee-high) and of the lift. Results: A total of 14 healthy young adults without diabetes participated. MCoT, RPE and SW were significantly higher for all CW conditions compared to the control, with less consistent results for asymmetry measures. MCoT was not significantly different across CW height or lift condition although an unexpected interaction between limb and CW height n was observed; MCoT was lower in the knee-high CW with vs. without a lift but did not change in the ankle-high CW based on lift status. Similarly, neither SW nor SIs changed in expected fashions across conditions. In contrast, RPE was significantly lower using the ankle- vs. knee-high CW and when using a lift vs no lift, with no significant interaction. Conclusions: Although metabolic costs were unaffected by CW design changes, which may reflect the absence of anticipated changes in kinematics that impact MCoT, perceived exertion was reduced through such changes. Unanticipated biomechanical changes may reflect a complex interaction among a number of competing factors that dictate behavior and MCoT. The differing results in perception of exertion and metabolic costs might be due to participants’ perceived exertion being sensitive to the collective impact of interacting biomechanical factors, including those not quantified in this study. Future work should seek to directly evaluate the impact of CW design changes in patients with DFU and the relationship to adherence. Full article

Chamomile (Matricaria chamomilla L.) is a popular herb of great economic and medicinal value. Despite its significant potential, there are currently no commercially available varieties specifically adapted to Mediterranean low-input farming systems. The present study aimed to develop a genetically improved breeding population derived from indigenous Greek chamomile germplasm, following a multi-year strategy, based on pedigree selection under low-input conditions. This selection process constituted the first phase of the breeding program, during which selection focused on improving inflorescence dry weight and essential oil quality, particularly with respect to α-bisabolol and chamazulene content. After three cycles of selection, considerable genetic gains were achieved. The realized heritability values exceeded 0.5 for all assessed traits, confirming strong genetic control. In the fourth year, representing the second phase of the breeding program, the breeding population—developed through selection during the first phase—was evaluated alongside the initial population and commercial diploid and tetraploid varieties. The breeding population exhibited significant observed gains compared to the initial population: inflorescence dry weight increased by 12.17%, α-bisabolol content by 71.45%, and chamazulene content by 6.57%. Additionally, the breeding population not only surpassed all evaluated diploid genotypes in essential oil composition, but also displayed a chemotypic shift, indicating successful alignment with tetraploid varieties characterized by high-value chemical profiles. Furthermore, this selection process targeting specific commercial chamomile traits indirectly contributed to improvement in plant height and inflorescence morphology. Overall, these results demonstrate that conventional breeding, when applied effectively to native resources, can enhance both agronomic performance and essential oil profile. The newly developed breeding population provides a strong foundation for future cultivar development tailored to Mediterranean low-input sustainable farming systems. Full article

Objectives: This study evaluated how different distributions of isometric conditioning activity (ICA) durations affect countermovement jump (CMJ) performance in highly trained male volleyball players compared to a control condition (CTRL). Methods: Twelve participants performed CTRL and three ICA protocols in a half-back squat: 9 s (3 × 1 × 3 s), 27 s (3 × 3 × 3 s), and 45 s (3 × 5 × 3 s). CMJ height was measured before and at 3, 6, 9, and 12 min post ICA. Results: A two-way repeated measures ANOVA showed significant main effects of time (F = 3.820; p = 0.009) and condition (F = 6.451; p = 0.001), with no significant interaction (F = 1.484; p = 0.138). Post hoc analysis indicated significant CMJ height increases at 9 min [mean difference (MD) = 5.1 ± 0.6 cm; p = 0.045] and 12 min (MD = 6.0 ± 1.4 cm; p = 0.010) post ICA. Moreover, CMJ height was significantly greater in the 27 s (MD = 10.0 ± 0.6 cm; p = 0.002) and 45 s (MD = 7.3 ± 2.0 cm; p = 0.035) conditions compared to the 9 s protocol. Conclusions: Incorporating ICAs of 9 s or 45 s into warm-up routines can enhance CMJ performance, although these durations may elicit different neuromuscular adaptations and movement strategies. Full article

Heterodera schachtii, a nematode primarily feeding on sugar beet and cruciferous plants, e.g., rapeseed, cabbage, broccoli, mustard, and radish, had a significant impact on Camelina sativa (L.) Crantz. The isolation of H. schachtii cysts from C. sativa roots and a known data gap regarding their development on this plant prompted an investigation into their interaction. A pot experiment conducted under controlled conditions in a growth chamber showed that H. schachtii completes its full development cycle in the roots of spring (UP, Smielowska, Borowska, Omega) and winter (Lemka, Maczuga, Luna, Przybrodzka) camelina cultivars at temperatures of 15, 20, and 25 °C. Female nematodes and cysts were most abundant in the Omega cultivar at 20 °C, averaging 9.25 per plant. Nematode feeding did not affect the height or fresh weight of the plants. Plants of the Przybrodzka cultivar had fewer leaves than the control plants. More siliques were observed on the control plants of the UP cultivar kept at 15 °C and those of the UP and Borowska cultivars at 20 °C. Under natural conditions, the number of eggs and larvae in the soil decreased by approximately 50% during the camelina growth cycle for both spring and winter biotypes. Full article

Despite our preliminary research about the inductive effect of exogenous abscisic acid (ABA) on the weed-suppressive activity of rice in a hydroponic system, there is a lack of knowledge regarding the induction mechanism for ABA application to enhance the ability for weed control underground. Here, two pot experiments using rice–barnyard grass mixed culture were conducted to investigate the effects of exogenous ABA treatment on weed inhibition strategies in both allelopathic rice PI312777 (PI) and non-allelopathic rice Lemont (Le). The largest observed weed inhibition changes in the two rice accessions both occurred with the 9 μmol/L ABA treatment. ABA induction on PI significantly increases the inhibitory effect on the plant height of barnyard grass with root contact and root segregation by 25.7% and 19.1%, respectively, with 23.5% increases observed in Le rice with root contact and no significant increases in plants with root segregation with nylon mesh. ABA induction also significantly increased the root distribution in the soil of Le. Compared with the uninduced group, ABA treatment significantly elevated the total amounts of reversibly adsorbed phenolic acids in the two soil layers of PI and the irreversibly adsorbed phenolic acids in Le soil layers. Furthermore, exogenous ABA could change the bacterial composition in rhizosphere soil of the two rice accessions, with the change in the species composition in the rhizosphere soil of the allelopathic rice PI being greater. Importantly, the bacterial compositions (Anaerolineales, Bacteroidales, and Myxococcale) in the PI rhizosphere soil of rice induced by ABA were more related to the contents of reversibly adsorbed phenolic acids in the soil. However, the core bacterial compositions that promote plant growth (Sphingomonadales, Cyanobacteriales, and Rhizobiales) in the Le rhizosphere soil were more related to the contents of irreversibly adsorbed phenolic acids in the soil. These findings suggested that the ABA induction mainly changed root distribution and core bacterial compositions in Le to enhance resource competition, whereas it stimulated the release of reversibly adsorbed phenolic acids to modulate the specific bacterial compositions in rhizosphere soil of PI and to strengthen allelopathic effects. Full article

Indoor environments have received increasing attention in recent years, and achieving high-quality indoor conditions has become increasingly important. Underfloor air distribution (UFAD) systems have attracted significant interest due to their potential to improve ventilation efficiency, enhance thermal comfort, and reduce energy consumption. Compared with overhead air distribution (OHAD) systems, UFAD not only offers better energy savings but also demonstrates improved thermal stratification performance. However, most previous studies have relied on numerical simulations to evaluate UFAD performance under specific system designs or scenarios. Few studies have conducted on-site measurements to investigate the combined effects of multiple air-conditioning settings, which are closely related to user control strategies. This study experimentally evaluated the cooling performance and thermal comfort of a UFAD system under different control configurations. By combining variations in airflow rate, temperature setpoints, and supply air distribution, a total of 12 test configurations were examined. The results indicate that configurations with lower temperature setpoints achieved the highest cooling performance. Most test settings produced neutral thermal conditions at heights between 120 and 180 cm, while areas at 60 cm or below were noticeably cooler. These findings provide practical guidance for users in controlling UFAD systems. Full article

Background/Objectives: In early-stage diabetes, diastolic dysfunction is an initial indicator of heart failure and is linked to altered glucose metabolism, including in prediabetes. Based on initial evidence that Calanus oil, derived from Calanus finmarchicus, which is rich in omega-3 polyunsaturated fatty acids and other bioactive compounds, benefits metabolic and cardiorespiratory health, this proof-of-principle study aimed to assess whether Calanus oil improves diastolic function in prediabetic women. Methods: Twenty middle-aged, obese women with prediabetes and no history of cardiac complications were enrolled and received 4 g/day of Calanus oil, providing 276 mg EPA + 256 mg DHA, for 12 weeks. Systolic and diastolic cardiac function, including the E/A ratio (E/A), was assessed by echocardiography. In addition, central blood pressure (BP) and pulse wave velocity (PWV) were analyzed by oscillometry. Metabolic health was evaluated using composite markers, including the metabolic syndrome severity score (Met-S score) and the triacylglycerol glucose–waist-to-height ratio (TyG-WHtR). Results: E/A was significantly improved (p = 0.023) following 12 weeks of Calanus oil supplementation. Furthermore, a significant improvement in metabolic health, indicated by a reduced Met-S score and a lower TyG-WHtR, was noticed (p < 0.001, respectively), reflecting decreased metabolic syndrome severity and enhanced insulin sensitivity. In addition, a significant reduction in diastolic BP, resting heart rate (p = 0.047), but not PWV or systolic BP (all p > 0.05) was observed. The improvement in E/A was associated with improved insulin sensitivity, as reflected by a decrease in the TyG-WHtR (p = 0.014). Conclusions: These exploratory findings suggest that Calanus oil supplementation in pre-diabetic women might improve central diastolic haemodynamics, accompanied by an overall improvement in metabolic health. However, the absence of a placebo control group limits definitive conclusions. Full article

The global demand for high-protein soybeans is rapidly increasing, driven by the growing popularity of healthy foods and plant-based protein products. To address this demand, a novel high-protein soybean variety, Jinyuan 601, was developed through a systematic breeding program. This study details the breeding process, agronomic characteristics, and performance evaluation of Jinyuan 601, which was derived from a cross between Heihe YX10-534 (female parent) and Heihe No. 45 (male parent). The variety was selected over multiple generations (F₂–F₇) and stabilized as Heihe 18-250, demonstrating excellent quality, upright stalks, and resistance to diseases and pests. Jinyuan 601 exhibits a protein content of 43.66% and a fat content of 17.21%, meeting the standard for high-protein soybeans (≥43% protein). It has a growth period of 111 days, with a plant height of 93.2 cm, and shows moderate resistance to soybean mosaic virus (SMV). Yield trials conducted over two years (2021–2022) produced an average of 2292 kg ha⁻¹, representing a 3.0% increase over the control variety (Huajiang No. 2). This variety holds significant potential for applications in health foods, plant-based products, and sustainable agriculture, contributing to food security and reducing reliance on soybean imports. Full article

Bifacial Photovoltaic (bPV) technology is rapidly becoming the standard in the solar photovoltaic (PV) industry due to its ability to capture reflected radiation and generate additional energy. This experimental study analyses the electrical performance of bPV modules under specific installation conditions, including varying heights, module tilt angles (MTA), and surface reflectivity. The methodology combines controlled indoor testing with outdoor experiments that replicate real-world operating environments. The outdoor test setup was carefully designed and included dual data acquisition systems: one with independent sensors and another with wireless telemetry for data transfer from the inverter. A thermal performance model was used to estimate energy output and was benchmarked against experimental measurements. All electrical parameters were obtained in accordance with international standards, including current-voltage characteristic (I–V curve) corrections, using calibrated instruments to monitor irradiance and temperature. Indoor measurements under Standard Test Conditions yielded at bifaciality coefficient $\phi =0.732$, a rear bifacial power gain $BiFi=0.285$, and a relative bifacial gain $BiF{i}_{rel}=9.4\%$. The outdoor configuration employed volcanic red stone (Tezontle) as a reflective surface, simulating a typical mid-latitude installation with modules mounted 1.5 m above ground, tilted from 0° to 90° regarding floor and oriented true south. The study was conducted at a site located at 18.8° N latitude during the early summer season. Results revealed significant non-uniformity in rear-side irradiance, with a 32% variation between the lower edge and the centre of the bPV module. The thermal model used to determine electrical performance provides power values higher than those measured in the time interval between 10 a.m. and 3 p.m. Maximum energy output was observed at a MTA of $0°$, which closely aligns with the optimal summer tilt angle for the site’s latitude. Bifacial energy gain decreased as the MTA increased from $0°$ to $90°$. These findings offer practical, data-driven insights for optimizing bPV installations, particularly in regions between $15°$ and $30°$ north latitude, and emphasize the importance of tailored surface designs to maximize performance. Full article

Accurate classification of tree species is crucial for forest management and biodiversity conservation. Remote sensing technology offers a unique capability for classifying and mapping trees across large areas; however, the accuracy of extracting and identifying individual trees remains challenging due to the limitations of available imagery and phenological variations. This study presents a novel integrated machine learning (ML) and Geographic Object-Based Image Analysis (GEOBIA) framework to enhance tree species classification in a botanical garden using multi-temporal unmanned aerial vehicle (UAV) imagery. High-resolution UAV imagery (2.3 cm/pixel) was acquired across four different seasons (summer, autumn, winter, and early spring) to incorporate the phenological changes. Spectral, textural, geometrical, and canopy height features were extracted using GEOBIA and then evaluated with four ML models (Random Forest (RF), Extra Trees (ET), eXtreme gradient boost (XGBoost), and Support Vector Machine (SVM)). Multi-temporal data significantly outperformed single-date imagery, with RF achieving the highest overall accuracy (86%, F1-score 0.85, kappa 0.83) compared to 57–75% for single-date classifications. Canopy height and textural features were dominant for species identification, indicating the importance of structural variations. Despite the limitations of moderate sample size and a controlled botanical garden setting, this approach offers a robust framework for forest and urban landscape managers as well as remote sensing professionals, by optimizing UAV-based strategies for precise tree species identification and mapping to support urban and natural forest conservation. Full article

To investigate the effects of seasonal grazing on ground-dwelling insect communities in desert steppe, this study conducted a controlled experiment in the desert steppe of Yanchi County, Ningxia, during 2022–2023. Five grazing regimes were established: spring-summer grazing (Sp+Su), spring-autumn grazing (Sp+Au), summer-autumn grazing (Su+Au), year-round continuous grazing (Annual), and no grazing (Control, CK). Insects were collected using pitfall traps and categorized into herbivorous and predatory functional groups. Combined with monitoring of vegetation community structure, we analyzed the regulatory mechanisms of grazing on insect diversity. The results showed that different grazing regimes had significantly divergent effects on herbivorous and predatory insects. Herbivorous insect diversity was significantly highest under the Annual grazing regime, while Sp+Au grazing effectively controlled herbivorous insect occurrence, resulting in the lowest abundance. Predatory insects exhibited the highest abundance but the lowest diversity under Su+Au grazing, whereas the CK regime increased their species richness. Beta diversity analysis indicated that total replacement diversity (Repl) was dominant, suggesting that grazing primarily influenced community structure by altering species composition rather than changing species number. Non-metric multidimensional scaling (NMDS) results revealed clustering characteristics of insect community structures under different grazing regimes. Redundancy analysis (RDA) and generalized additive models (GAMs) identified vegetation height and predatory insect abundance as key factors driving changes in herbivorous insects. Vegetation density and biomass exhibited nonlinear regulatory effects on herbivorous insects. Based on these findings, we recommend adopting either a hybrid strategy of “year-round continuous grazing combined with seasonal rest” or specifically the “spring + autumn” (Sp+Au) grazing regime. These approaches aim to synergistically achieve the goals of pest control and biodiversity conservation in desert steppe ecosystems. Full article

A systematic investigation was conducted on the laser shock forming (LSF) process of carbon steel Q355ME sheets and practical skin components, focusing on the influence of absorption layer types, laser energy, and impact cycles on forming capacity and surface properties. Three kinds of absorbing layers were compared in the experiment: no absorbing layer, 0.1 mm aluminum foil and 0.12 mm black tape. The results show that when the black tape is used as the absorbing layer, the forming effect is the best, the arc height value reaches 2.63 mm, and the radius of curvature is 1066 mm. Using 0.1 mm thick black tape as the absorption layer and laser parameters of 10% overlap rate, 15 ns pulse width, 4 mm spot, and 1064 nm wavelength, the single impact of 13 J, 15 J, and 17 J, and one, two, and three impacts of 15 J energy were carried out on the plate. It was found that the increase in laser energy and impact times resulted in increases in deformation, surface roughness, microhardness, and residual stress of the plate. The surface work hardening phenomenon of Q355ME plate after laser shock slowed down the increase in these performance parameters. The experimental results show that the laser energy is linearly positively correlated with the residual stress in a certain energy range. Under the optimized laser process parameters, the forming error of the actual skin parts is controlled within ± 0.4 mm, the surface residual stress increases by 368.9%, and the surface microhardness increases by 10.4%. The ultra-high strain plastic deformation and grain refinement on the surface of the sheet were caused by multiple laser shock peenings, which confirmed that LSF technology can improve the formability of carbon steel skin parts and improve its surface properties. Full article

This article focuses on how to further explore the impact of building layout and form on the local wind environment in micro scale ventilation corridors connected to the urban scale. Taking Shijiazhuang as the research area, three typical blocks of complex building forms, including old and new ones, were selected near the built ventilation corridors. CFD numerical simulation and on-site observation experiments were conducted to analyze the impact of different building heights and layouts on the wind environment in each typical block qualitatively and quantitatively. The above can provide a reference and guidance for the construction of secondary and tertiary ventilation corridors and the spatial form design of functional buildings during urban renewal in the stock era. The results show the following: (1) average wind speed, Mean Wind Velocity ratio, and the proportion of the outdoor pedestrian comfort zone are negatively correlated with the building height, but there is a threshold for them to decrease with the increase in the building height. Observation experiments also indicate that in the background of the south wind, the internal and leeward wind environment of new high-rise residential areas is better than that of old low residential areas. (2) Regression analysis was conducted between the simulated average wind speed and the building height, indicating that regulating the average building height to be below 45 m can improve the wind environment as the building height decreases. (3) The enclosed building complex has the smallest impact distance on downstream wind speed compared to point, row, and staggered layouts, but its internal ventilation environment is relatively poor. To ensure the ventilation performance, the upper limit of the building height should be stricter, and it should be controlled within at least 40 m, especially below 30 m. (4) In the process of urban renewal in the future, it is recommended to conduct an overall ventilation efficiency evaluation for different blocks. Compared to others, increasing the height of buildings and leaving more space to increase the inter site ratio/building spacing is more beneficial for the overall ventilation environment. Full article