Search Results (9,088)

Structural safety of transmission towers is directly influenced by the behavior of bolted connections at discontinuity joints in the main steel angles. Thus, it is essential to investigate the axial compression behavior of double-shear splice connections of main steel angles. In this study, a total of 10 groups of discontinuous steel angle specimens with double-shear splice connections, comprising eight groups of specimens with the same upper and lower angles and two groups of specimens with different upper and lower angles, were designed and tested in compression. The axial deformation, out-of-plane deflection, and strain at the mid-height of steel angles were measured to analyze the influence of double-shear splice connections on the compression behavior of steel angles. Moreover, comparisons were made among discontinuous steel angles in terms of the ultimate load and the associated deformation to investigate the effects of splice steel ratio, slenderness, bolt spacing, and bolt torque, respectively. Based on the experimental results of steel angles in compression, comparisons with the values calculated using Chinese design codes suggest that present design methods show limited accuracy in calculating the axial compressive load capacity of steel angles with double-shear spliced connections, indicating the necessity for revising the design methods in relevant codes. Full article

The Elfeija Dune Field (EDF) is a continental aeolian system in an arid region of southeastern Morocco. Studying this system is critical for understanding the effects of mounting climatic and anthropogenic pressures. This study provides a comprehensive characterization of the EDF’s morphology, sedimentology, aeolian dynamics, genesis, and recent evolution. A multi-scale, multidisciplinary approach was adopted, integrating field observations, sedimentological analyses, MERRA-2 reanalysis wind data, cartographic analysis, digital terrain modeling, and morphometric measurements. The results reveal an active 30 km² dune field, elongated WSW-ENE, which is divisible into three morphodynamic zones with a high dune density (80–90 dunes/km²). The wind regime is predominantly from the W to WSW, driving a net ENE sand transport and creating conditions conducive to barchan formation (RDP/DP > 0.78). Sediments are quartz dominated, with significant calcite and various clay minerals (illite, kaolinite, and smectite). Dune sands are primarily fine- to medium-grained and well sorted, in contrast to the more poorly sorted interdune deposits. The landscape is dominated by barchans (mean height H = 2.5 m; mean length L = 50 m) and their coalescent forms, indicating sustained aeolian activity. The potential sand flux was estimated at 1.7 kg/m/s, with a dune collision probability of 32%. The field’s genesis is hypothesized to be controlled by a topographically induced Venturi effect, with an initiation approximately 1000 years ago, potentially linked to the Medieval Climatic Optimum. Significant anthropogenic impacts from expanding irrigated agriculture are observed at the dune field margins. By providing a detailed characterization of the EDF and its sensitivity to natural and anthropogenic forcings, this study establishes a critical baseline for the sustainable management of arid environments. Full article

Background and Objectives: The Nordic hamstring exercise (NHE) effectively strengthens the hamstrings, reduces the risk of hamstring strain, and induces fatigue in the muscles; thus, post-NHE recovery strategies should be optimized. Foam rolling (FR) is a widely used method, with the belief that it can speed up recovery. Thus, this study investigated the acute and 48-h effects of FR following the NHE on muscle stiffness, pain pressure threshold (PPT), flexibility, countermovement jump (CmJ) height, and maximal voluntary isometric contraction (MVIC). Materials and Methods: Thirty-two active males were randomly assigned to either an FR group (n = 16) or a passive recovery (PR, n = 16) group. Measurements were taken at three time points: pre-test, post-test_0h, and post-test_48h. Participants performed the NHE (3 sets × 10 reps) before the recovery interventions. Variables assessed included muscle stiffness (MyotonPro), flexibility (sit and reach), PPT (algometer), jump performance (force platform), and MVIC peak torque (dynamometer). Results: FR significantly improved acute flexibility (12.7%, p < 0.001) following the NHE and prevented flexibility loss at 48 h, compared to the PR group. However, FR showed no significant advantages over PR in terms of muscle stiffness, PPT, CmJ, or MVIC, both acutely and at 48 h (p > 0.05). Conclusions: FR is an effective acute recovery strategy for improving flexibility after the NHE but offers limited effects for muscle stiffness, PPT, and other functional muscle parameters, both acutely and at 48 h. Further research should explore the long-term effects and efficacy of FR across diverse populations and recovery scenarios. Full article

Wind-blown sand concentrations decay rapidly and in an orderly manner with height above the surface. The saltation flux profiles are of interest to understand wind and sand interactions and for fundamental measurement and modeling of associated transport rates. This study compares methods to measure and represent aeolian sand flux profiles. We measured vertical flux profiles and used quality-controlled data to test power, logarithmic, and exponential functions to reproduce the profiles. These results are used in a pragmatic assessment of the efficiency of reproducing flux profiles from vertically discontinuous arrays of traps or sensors compared to profiles obtained from continuous vertical arrays of segmented traps. Our analysis corroborates previous findings demonstrating that exponential decay functions are statistically the best method to approximate flux profiles. The results are used in a novel application to compare flux profiles reproduced from vertically discontinuous arrays of devices with those obtained from continuous vertical arrays comprising nine mesh-style traps. The results indicate that discontinuous arrays of 3, 4, 5, or 6 devices deployed less than 200 mm from the surface will effectively reproduce results from the continuous array, with average errors less than 3%. Errors increase when devices are at greater heights or as the number of devices decreases. Discontinuous arrays typically do not capture creep transport which would contribute to error in our comparisons. Therefore, creep must comprise less than 3% of total aeolian sand flux, contradicting typical assumptions of 25%. Full article

Rapid and accurate identification of maize architecture characteristics is important for understanding both yield potential and crop breeding experiments. Most canopy architecture indicators cannot fully reflect the vertical leaf distribution in field environments. We conducted field experiments on sixty maize cultivars under four planting densities at three different sites, and herein introduce two novel indicators, “kurtosis and skewness,” based on the manually measured leaf area index (LAI) of maize at five different canopy heights. Then, we constructed the LAI, plant height (PH), kurtosis, and skewness estimation models based on unmanned aerial vehicle multispectral, RGB, and laser detecting and ranging data, and further assessed the canopy architecture and estimated yield. The results showed that the fitting coefficient of determination (R²) of cumulative LAI values reached above 0.97, and the R² of the four indicators’ estimation models based on multi-source data were all above 0.79. A high LAI, along with greater kurtosis and skewness, optimal PH levels, and strong stay-green ability, are essential characteristics of high-yield maize. Moreover, the four indicators demonstrated high accuracy in estimating yield, with the R² values based on measured canopy indicators at the four planting densities being 0.792, 0.779, 0.796, and 0.865, respectively. Similarly, the R² values for estimated yield based on estimated canopy indicators were 0.636, 0.688, 0.716, and 0.775, respectively. These findings provide novel insight into maize architecture characteristics that have potential application prospects for efficient estimation of maize yield and the breeding of ideal canopy architecture. Full article

This study explores the fabrication of hydrophobic surfaces on polymer components via Digital Light Processing (DLP), with emphases on how texture geometry, feature dimensions, and resin type influence surface wettability. Square and cylindrical microtextures were fabricated and evaluated using static contact angle measurements. Square-shaped structures demonstrated enhanced hydrophobicity, with contact angles reaching 133.6°, compared to approximately 100° for cylindrical counterparts of identical dimensions. Increasing pillar height to 521 µm enhanced hydrophobicity by approximately 15%, while decreasing pillar spacing to 150 µm increased contact angles from 86.8° to 106°, highlighting the role of microstructure density. For square-shaped structures, the addition of a hydrophobic agent at 3 wt.% resulted in a contact angle of 123.4°, representing a 44% improvement over the untreated sample. These findings underscore the combined influence of resin chemistry, surface texture design, and dimensional parameters on wettability behavior. Although superhydrophobicity (contact angle > 150°) was not achieved, the study demonstrates notable advancements in optimizing hydrophobicity through DLP printing. Overall, the results support DLP as a scalable and cost-effective approach for engineering functional surfaces suited to self-cleaning, biomedical, and anti-fouling applications. Full article

PM_2.5 is an air pollutant that has a direct link to increased cardiovascular and respiratory morbidity and mortality, which has been demonstrated in numerous studies. Existing research highlights species-specific variations in the capacity of trees to capture and retain particulate matter (PM). However, a critical gap remains regarding sensitivity analyses of i-Tree Eco model assumptions. Such analyses are crucial for validating the model’s PM deposition estimates against empirically derived efficiencies, a deficiency that the present study addresses. The study consisted of two steps: a tree inventory was carried out at three selected sites, based on which, an ecosystem service analysis was performed using i-Tree Eco, and samples were taken from the leaves of trees at the analysed sites, which were the basis for comparing the data from the i-Tree Eco method and laboratory methods. The study focused on comparing PM_2.5 and PM₁₀ removal estimates derived from both the model and laboratory measurements. The results revealed significant discrepancies between the modelled and laboratory values. A comparison of the average annual PM₁₀ accumulation measured using laboratory methods for individual tree species showed that Tilia sp. achieved 24%, Fraxinus sp. 47.6%, Aesculus sp. 50.77%, and Quercus robur 23.4% of the PM₁₀ uptake efficiency estimated by the i-Tree Eco model. For PM_2.5 uptake, the values obtained through both methods were more consistent. Furthermore, trees growing under more challenging environmental conditions exhibited smaller diameter at breast height (DBH) and lower PM₁₀ and PM_2.5 removal efficiency according to both methods. While I-Tree Eco incorporates tree biophysical characteristics and health status, its methodology currently lacks the resolution to reflect site-specific environmental conditions and local pollutant concentrations at the individual tree level. Therefore, laboratory methods are indispensable for calibrating, validating, and supplementing i-Tree Eco estimates, especially when applied to diverse urban environments. Only the combined application of empirical and model-based methods provides a comprehensive understanding of the potential of urban greenery to improve air quality. Full article

The aim of this study was to analyze the factors that may influence serum osteocalcin levels in children with osteogenesis imperfecta treated with intravenous sodium pamidronate and to define the role of osteocalcin assessment. The study included 61 patients diagnosed with osteogenesis imperfecta type 1 or 3, aged 2 to 18, hospitalized for intravenous sodium pamidronate administration. A retrospective analysis of medical records was conducted, collecting information on age, sex, body weight, height, the number of long bone fractures throughout life, serum levels of osteocalcin, creatinine, alkaline phosphatase, 25(OH)D₃, and DXA BMD z-scores for the L1–L4 spine segment. The concentration of osteocalcin is higher in patients with osteogenesis imperfecta than the reference ranges for sex and age. Patients diagnosed with type 3 have significantly lower osteocalcin levels compared to patients with type 1. Also, increasing the age-standardized pamidronate cycle rate significantly reduced osteocalcin concentration. The strongest predictor of osteocalcin concentration among the factors studied is the type of osteogenesis imperfecta. L1–L4 BMD value and fracture frequency were unrelated to osteocalcin concentration. Osteocalcin is an important marker of bone formation that should be measured at the beginning of treatment, as its concentration decreases after successive doses of bisphosphonates. Full article

Despite its value as a culinary, medicinal, and essential oil crop, caraway struggles to grow and develop its biochemical quality in drought-prone sandy soils. To tackle this challenge, we conducted two field trials under drip irrigation, testing four rates of organic manure (0, 5, 10, and 15 ton/hectare (ha) and three foliar biostimulants: vitamin B₁ (50 and 100 mg L⁻¹), vitamin E (50 and 100 mg L⁻¹), and active yeast (100 and 150 mL L⁻¹). We used a randomized split-plot design with three replicates, assigning manure rates to main plots and biostimulants to subplots. We measured plant height, stem diameter, branch number, dry biomass, umbels per plant, 1000-seed weight, seed yield (per plant and per ha), essential oil content, chlorophyll a and b, carotenoids, and leaf N, P, and K. All treatments outperformed the unfertilized control. Applying 15 ton/ha of manure alone increased mean plant height by 185.3 cm, stem diameter by 2.93 mm, branch number by 14.5, and herbal weight by 91.97 g across both seasons—a gain of about 11–15%. Foliar application of vitamin B₁ at 100 mg L⁻¹ (without manure) achieved even larger gains: mean plant height improved by 176.5 cm, stem diameter by 2.6 mm, branches number by 15.1, and herbal biomass by 103.95 g (20–36% growth increases). It also boosted essential oil yield by 1.89 mL per plant (16–50%) and enhanced nutrient uptake. The most pronounced synergy emerged when combining 15 ton/ha of manure with 100 mg L⁻¹ vitamin B₁, raising seed yield to 1698.8 kg/ha (35%), plant height to 184.7 cm (52%), number of branches to 17.4 per plant (56%), umbels to 38.1 per plant (42%), 1000-seed weight to 16.9 g (48%), and essential oil yield to 2.3 mL per plant (115%), compared to the control. Chlorophyll a increased by 50%, chlorophyll b by 33%, carotenoids by 35%, and leaf N, P, and K by 43%, 90%, and 76%, respectively. Manure combined with vitamin E or yeast delivered moderate improvements. These findings demonstrate that integrating organic manure with targeted foliar biostimulants—especially vitamin B₁—under drip irrigation, is a sustainable strategy to maximize caraway yield, oil content, and nutritional quality on marginal sandy soils. Full article

To improve the performance of green manure sowing and processing equipment, it is necessary to investigate the physical properties of seeds, including their dimensions, bulk density, and frictional characteristics. Focusing on the main cultivated varieties of green manure in China—milk vetch, hairy vetch, and sesbania—this study proposes three low-cost, convenient, and high-precision experimental methods to measure the geometric size of small seeds. The measured results show that the milk vetch seeds were 2.60–3.40 mm in length, 1.90–2.40 mm in width, and 0.71–0.97 mm in height. The hairy vetch pods were 23.03–32.83 mm in length, 7.39–9.74 mm in width, and 4.06–6.15 mm in height, and the seeds were 3.04–4.10 mm in diameter. The sesbania seeds were 3.81–4.29 mm in length, 1.98–2.37 mm in width, and 1.85–2.08 mm in height. The thousand-seed weights of milk vetch, hairy vetch, and sesbania seeds were 3.40 g, 26.50 g, and 15.58 g, with moisture contents of 7.18%, 9.81%, and 8.73%, respectively. The bulk densities of milk vetch, hairy vetch, and sesbania seeds were 732 g/L, 761 g/L, and 845 g/L. The angles of repose of milk vetch, hairy vetch, and sesbania seeds were 31.66°, 28.15°, and 29.82°, measured using an angle-of-repose tester. Sliding friction angles of 25.85°, 23.55°, and 24.03° for milk vetch, hairy vetch, and sesbania seeds were obtained using a dividing head. These methods and results provide valuable references for the measurement of the physical properties of small-seeded crops (e.g., green manures) as well as other small or irregularly shaped particles. Full article

The oriental river prawn (Macrobrachium nipponense) is one of the most popular freshwater prawn in China. In order to study the relationships between morphometric traits and body mass across different geographical locations and provide references of phenotypic traits for the breeding of M. nipponense, we collected wild M. nipponense from three locations (main stream, HH; Suyahu Reservoir, SYH; and Wuyue Reservoir, WY) in the upper reaches of the Huaihe River, China, and measured 26 morphometric traits and body masses. We found that the coefficient of variation of body mass varied from 31.88% to 59.27% across the three populations, exceeding that of morphometric traits within each population. All 26 morphometric traits, except for the fourth abdominals somite length in the WY population, were observed to correlate significantly positively with body mass (p < 0.05). A path analysis indicated that propodus length, body length, ischium length, carapace height, and second abdominals somite length in the HH population; body length, propodus length, abdominal height, sixth abdominals somite length, and telson length in the SYH population; and body length, carapace height, fifth abdominals somite length, and abdominal height in the WY population significantly affected body mass directly (p < 0.05). Comparing the pathway analysis with the grey relation analysis, we can conclude that the trait most correlated with body mass was body length across the three geographical populations. These findings provide references of waiting morphological traits for M. nipponense selective breeding in different geographical populations. Full article

Pinus taeda plantations have been facing declining productivity in South America, especially due to competition for natural resources such as light, water, and nutrients. Competition with spontaneous vegetation in the early years is one of the main constraints on growth and biomass allocation in trees. However, the best method and timing for weed control and its impact on the productivity of Pinus taeda plantations are unknown. This study aims to evaluate whether weed control increases the growth and above-ground biomass production of Pinus taeda plantations in southern Brazil. This study was conducted at two sites with five-year-old Pinus taeda plantations in southern Brazil, with each being submitted to different weed control methods. This study was conducted in randomized blocks, with nine treatments: (i) NC—no weed control, i.e., weeds always present; (ii) PC—physical weed control; (iii) CC–T—chemical weed control in the total area; (iv) CC–R—chemical weed control in rows (1.2 m wide); (v) C6m, (vi) C12m, (vii) C18m, and (viii) C24m—weed control up to 6, 12, 18, and 24 months after planting; and (ix) COC—company operational weed control. The following parameters were evaluated: the floristic composition and weed biomass, height, diameter, stem volume, needle biomass, branches, bark, and stemwood of Pinus taeda. Control of the weed competition, especially by physical means (PC), and chemical control over the entire area (CC–T) promoted significant gains in the growth and above–ground biomass production of Pinus taeda at five years of age, particularly at the Caçador site. The results reinforce the importance of using appropriate strategies for managing weed control to maximize productivity, especially before canopy closure. In addition, the strong correlation between growth variables and the total biomass and stemwood indicates the possibility of obtaining indirect estimates through dendrometric measurements. The results contribute to the improvement of silvicultural management in subtropical regions of southern Brazil. Full article

Nitrogen dioxide (NO₂) plays a crucial role in environmental processes and public health. In recent years, NO₂ pollution has been monitored using a combination of in situ measurements and satellite remote sensing, supported by the development of advanced retrieval algorithms. With advancements in satellite technology, large-scale NO₂ monitoring is now feasible through instruments such as GOME-2C and TROPOMI. However, the fixed local overpass times of polar-orbiting satellites limit their ability to capture the complete diurnal cycle of NO₂, introducing uncertainties in emission estimation and pollution trend analysis. In this study, we evaluated differences in NO₂ observations between GOME-2C (morning overpass at ~09:30 LT) and TROPOMI (afternoon overpass at ~13:30 LT) across three representative regions—East Asia, Central Africa, and Europe—that exhibit distinct emission sources and atmospheric conditions. By comparing satellite-derived tropospheric NO₂ column densities with ground-based measurements from the Pandora network, we analyzed spatial distribution patterns and seasonal variability in NO₂ concentrations. Our results show that East Asia experiences the highest NO₂ concentrations in densely populated urban and industrial areas. During winter, lower boundary layer heights and weakened photolysis processes lead to stronger accumulation of NO₂ in the morning. In Central Africa, where biomass burning is the dominant emission source, afternoon fire activity is significantly higher, resulting in a substantial difference (1.01 × 10¹⁶ molecules/cm²) between GOME-2C and TROPOMI observations. Over Europe, NO₂ pollution is primarily concentrated in Western Europe and along the Mediterranean coast, with seasonal peaks in winter. In high-latitude regions, weaker solar radiation limits the photochemical removal of NO₂, causing concentrations to continue rising into the afternoon. These findings demonstrate that differences in polar-orbiting satellite overpass times can significantly affect the interpretation of daily NO₂ variability, especially in regions with strong diurnal emissions or meteorological patterns. This study highlights the observational limitations of fixed-time satellites and offers an important reference for the future development of geostationary satellite missions, contributing to improved strategies for NO₂ pollution monitoring and control. Full article

Static stretching (SS) is commonly used in athletic programs, and the intensity of SS has recently been examined for its effects on range of motion (ROM), strength and passive stiffness. However, the reliability of high-intensity SS across multiple testing sessions has not been investigated. The purpose of this investigation was to examine the reliability of high-intensity SS of the hamstrings across five laboratory visits on ROM, strength, power and passive stiffness. Thirteen physically active males (age: 26 ± 4 years, height: 180 ± 8 cm, body mass: 81 ± 10 Kg) underwent five repeated measures of laboratory SS on an isokinetic dynamometer where point of discomfort (POD) was measured, followed by a 30 s stretch at 120% POD. Across the visits, the pooled intraclass correlation coefficient was good for knee extension ROM (0.82), knee flexion strength (0.81) and passive stiffness (0.81). The ROM achieved to determine the POD before the SS was not different for the five visits (p = 0.370). These findings suggest high-intensity SS to 120% POD on an isokinetic dynamometer is reliable across multiple testing sessions. It is not clear if high-intensity static stretching is also reliable within applied scenarios and warrants further investigation. Full article

(1) Background: This study aimed to compare alveolar bone preservation and early healing outcomes following a comprehensive laser-assisted post-extraction protocol compared to conventional extraction alone. In addition, the potential influence of serum vitamin D levels on bone regeneration was assessed. (2) Methods: Thirty tooth extractions were performed and randomized into two groups: a test group (G1, n =15) and a control group (G2, n = 15). G1 received a laser-assisted protocol using Er:YAG and Nd:YAG lasers for granulation tissue removal, socket disinfection, clot stabilization, de-epithelialization, and photobiomodulation (PBM) with the Genova handpiece (LightWalker, Fotona, Slovenia). G2 underwent standard mechanical extractions and socket debridement without laser. (3) Results: Procedures in G1 were on average 8.7 min longer, but patients in this group reported significantly lower postoperative pain during the first three days (p < 0.05). A statistically significant difference in alveolar height was observed at the distal lingual site (25.4 mm vs. 21.7 mm; p = 0.046), with other sites showing a trend toward significance. Cumulative bone preservation, measured by Bone Loss Index (BLI4), was significantly better in the laser group. Notably, a positive correlation was found between serum vitamin D levels and bone preservation: each 1 ng/mL increase in vitamin D corresponded to a 0.18 mm gain in alveolar height (p = 0.021). (4) Conclusions: The comprehensive laser-assisted post-extraction protocol reduced postoperative pain and improved alveolar bone preservation, particularly at the lingual distal site. Serum vitamin D levels positively correlated with healing outcomes, suggesting a potential synergistic role of systemic and local regenerative factors. Full article