Marine vessels undergo wave-induced motions that amplify impact loads during ship-based aircraft landings, challenging the structural integrity and service safety of aero-engine isolation systems. To address this challenge, this study establishes a coupled ship-fuselage-engine model, investigating the damping performance of a turboprop engine isolation system under impact loads induced by ship heave. The model establishes an equivalent representation of the dynamic interaction between wave-induced ship heave motion and landing impact. It is experimentally validated using a high-energy drop-impact test platform, demonstrating high predictive accuracy with maximum deviations below 5% in vibration amplitude and under 8% in pulse width. As the ship heave velocity increases from 0 to 0.793 m/s, the peak vibration amplitudes rise significantly from 52.48 to 86.72 m/s 2 at the front-left position, from 55.17 to 93.88 m/s 2 at the front-upper position, and from 64.54 to 107.05 m/s 2 at the rear-left position. Further analysis reveals that the damping efficiency of the front isolators improves notably with increasing impact energy, attributed to the nonlinear hysteretic behavior of the isolation rubber. These findings provide valuable insights for optimizing aero-engine isolation systems in shipboard landing applications.

Ecosystem services play a vital role in supporting human life and environmental sustainability. However, tourism activities in Badung Regency, Bali, have led to significant changes in land cover and use, impacting the function of ecosystem services. This study integrates remote sensing, machine learning, and InVEST technology to understand the impact of Land Use/Land Cover (LULC) changes on ecosystem services in Badung Regency. The results show a decrease in non agricultural vegetation area from 17659.65 hectares in 2014 to 11405.84 hectares in 2024. Meanwhile, built-up land experienced a drastic increase from 15074.47 hectares in 2014 to 22134.06 hectares in 2024. In addition, the InVEST model shows a decrease in carbon stock by 1379,841.68 tons in the period 2014 to 2024. Meanwhile, water yield, nitrogen export, and sediment export increased, reflecting a relationship between tourism development and the decline in ecosystem services. Correlation analysis shows a consistent negative correlation between water yield and carbon stock, as well as a positive correlation between nitrogen export and sediment export. The results of this study are expected to serve as a reference for further studies on the dynamics of ecosystem services and support sustainable environmental management efforts in areas with rapidly growing tourism activity.

Researchers comparing countermovement (CMJ) and assisted countermovement (ACMJ) jumps reported conflicting findings on the landing impact force (LIF). This was likely due to differences in the landing strategies used. As the magnitude of LIF may have implications on neuromuscular adaptations, the purpose of this study was to compare the LIF between CMJ and ACMJ while adopting soft and stiff landing strategies. Thirteen resistance-trained athletes (sex: female = 5, male = 8, 26.4 ± 3.7 years, 68.4 ± 13.6 kg, 167 ± 5.1 cm) performed three CMJ and ACMJ each at 60%, 70%, 80% and 90% of bodyweight with instructions to either land soft or stiff on a force plate. Repetitions were separated by 30 s and conditions by 3 min. Resistance bands were used to induce the required weight during ACMJ. Data obtained regarding the average of the two closest trials based on jump height was analysed. Jump height significantly increased with increasing assistance during ACMJ for both landing conditions (p < 0.001). Propulsion duration (PD) was significantly shorter with increasing assistance during ACMJ for both landing conditions (p < 0.001). Peak and mean propulsion force significantly decreased with increasing assistance during ACMJ for both landing conditions (p < 0.001 and p < 0.001, respectively). The LIF was significantly greater with increasing assistance during ACMJ in the stiff-landing condition only (p < 0.001). Greater assistance allowed participants to jump higher while reducing PD. The higher LIF observed during stiff landing with greater assistance during ACMJ could be attributed to greater jump height and downward velocity during landing.

This study aimed to compare lower-body kinematics, muscle activity, performance, and vertical ground reaction force (GRFz) metrics between professional and varsity Ecuadorian football players during countermovement jumps with arm swing (CMJAS) and approach jumps (AJ). These two jump types were selected because they closely reflect common football-specific movement patterns; CMJAS simulates vertical jumps with arm drive, while AJ mimics explosive jumping after a run-up. Forty athletes (20 professional, 20 varsity; equally distributed by sex) were assessed using synchronized motion capture, force plates, and surface electromyography. Professional males demonstrated greater force production efficiency, defined here as the ability to generate higher concentric average GRFz, higher braking peak GRFz, shorter movement durations, and higher rates of force development in the unloading, yielding and braking phases, while achieving similar jump heights and modified reactive strength index (RSI mod) to varsity players during CMJAS. However, they also experienced higher impact forces in the AJ. Among females, professionals outperformed varsity players in both jumps, achieving greater jump heights, higher RSI mod scores, and increased concentric average GRFz. They also exhibited higher landing impact forces, loading rates, and asymmetric vastus medialis mean activation during landing; patterns commonly associated with elevated injury risk. Across groups, joint range of motion (ROM) and muscle activation patterns varied by phase, with professionals generally showing more proximal muscle activation and neuromuscular control. Asymmetries in ROM and muscle activation were more pronounced among professional females, particularly during AJ, suggesting task-specific adaptations that may also influence injury susceptibility. These findings underscore the importance of a comprehensive biomechanical assessment to inform injury screening and targeted strategies for injury risk reduction in competitive football.

The study was conducted during 2015–16 (November 2015-April 2016) at the Bankura district of West Bengal, India to assess the impact of land uses of Bankura on soil properties by sampling and analyzing soils from diverse representative plots from forests, orchards, pastures, cultivated fields, and uncultivated fallow lands that existed over the last decade. The average bulk density was highest at 1.38 g cm-3 in orchard land and lowest at 1.24 g cm-3 in pasture land, and increased with depth. The mean particle density varied from 2.53 g cm-3 in pasture to 2.69 g cm-3 in orchard, and also increased with depth. The total porosity was maximum in orchard (53.97%) and minimum in pasture (45.57%), and varied with depth. Moisture content was greatest in cultivated land (8.98%) and least in pasture (4.23%), whereas mean maximum water holding capacity was greatest in forest land (37.11%) and least in fallow land (29.05%), and both rose with depth. Soil pH was greatest in pasture (6.75) and least in cultivated land (5.61), and electrical conductivity was similarly distributed. Organic carbon content was greatest in forest land (0.41%) and least in cultivated land (0.16%), and decreased with depth. Available nitrogen, phosphorus, and potassium content were greatest in forest land and lowest in cultivated land, and decreased with an increase in soil depth. Pearson's correlation revealed significant correlations between soil properties.

ABSTRACT The carbon storage capacity of the Mongolian Plateau (MP) is easily ignored compared to other ecological services, due to its vast steppes and diverse arid and semi‐arid landscapes. However, the impact of Land Use/Land Cover (LULC) changes on carbon storage (CS) remains unclear, limiting climate‐adaptive land policies. This research combined with the PLUS and InVEST models to assess the dynamic characteristics of LULC and CS in the MP from 2000 to 2030, and introduced the elastic coefficient to quantify the CS changes caused by LULC change. These findings indicate that the CS in the MP were 21.45 Pg, 21.51 Pg, 21.70 Pg and 21.82 Pg in 2000, 2010, 2020 and 2030 respectively. Among various LULC types, grassland CS made up approximately half of the total CS during 2000–2020, yet degradation causes a carbon loss of 10.43 Tg. The largest reduction in CS mainly stems from the reduction of forest, leading to a loss of 35.57 Tg. Conversely, the land restoration by the conversion of barren land to grassland led to the greatest increase in CS, with a growth of 291.15 Tg. It reveals that the LULC dynamic changes on the MP caused carbon loss was marginally less than the carbon increase, and the capacity of the regional carbon sink can be effectively increased through land restoration measures, such as reforestation, returning grazing to grassland and desertification control.

Land use/cover (LULC) type change is one of the important causes of global change and the imbalance of the carbon cycle. Investigating the temporal variation in regional soil organic carbon storage (Rsoc) driven by LULC change is of great significance for scientifically guiding sustainable regional land management and facilitating the realization of China’s “dual carbon” objectives. Focusing on the main stream of the Tarim River, based on the LULC data of 1990, 2000, 2010, and 2020, combined with the data of soil organic carbon (SOC) content and soil bulk density, the temporal variation in the LULC and its impact on the Rsoc in the main stream of the Tarim River were analyzed. The results indicate that the LULC exhibited a pattern of “slow change—sharp change—slow change” across the three periods 1990–2000, 2000–2010, and 2010–2020. Grassland (GL) area consistently declined, while other types of LULC fluctuated during the period 1990–2020. The type and area of LULC conversion varied across the three periods: 1990–2000, 2000–2010, and 2010–2020. The area of the GL and bare land (BL) conversion was greater than that of conversion between other LULC in all three periods. The total amount of soil organic carbon (Tsoc) associated with different LULC types in the main stream of the Tarim River varied in 1990, 2000, 2010, and 2020, with the GL contributing the highest SOC levels, and conversion from the BL to GL had the largest increase in the Tsoc for the BL among the three periods, which was 0.20 × 1010~0.31 × 1010 kg, 0.97 × 1010~1.48 × 1010 kg, and 0.04 × 1010~0.06 × 1010 kg during1990–2000, 2000–2010, and 2010–2020 periods, respectively. Overall, the Rsoc in the 0–100 cm soil layer decreased from 2.18 × 1010 to 2.18 × 1010 kg during the period 1990–2020 in the main stream of the Tarim River.

Land use/cover (LULC) changes has a fundamental effect on the hydrological components in the Lake Tana Basin. The Lake Tana Basin, the source origin of the Blue Nile, has experienced notable LULC transitions over the past two decades. The present study evaluates the effect of land use/cover (LULC) changes on hydrological components in the Lake Tana basin using the soil and water assessment tool (SWAT). Two LULC maps, one from the International Livestock Research Institute (ILRI) for 2004 and another developed from Landsat 8 images for 2021, were used. Both models were calibrated and validated by SUFI-2 using observed discharge data, results showed strong performance (NSE > 0.79, R2 > 0.79 calibration; NSE > 0.90, R2 > 0.94 validation). Between 2004 and 2021, agricultural land decreased by 10.2% and forest cover declined by 33.1%, while wetlands and rangelands increased by 81.4 and 299.2%, respectively. Moreover, urban land was presented as a new class. These changes affected the basin’s hydrology as surface runoff increased from 111.6 to 118 mm/year (+ 5.8%), lateral flow decreased from 106.3 to 100.7 mm/year, and shallow aquifer evaporation declined by 10.2%. Evapotranspiration remained nearly constant at 1066 mm/year dominated by the lake evaporation. The results confirm the significant influence of LULC changes on the hydrological components of the Lake Tana Basin which highlight the need for sustainable land and water management.

Abstract Focusing on the development requirements for enhancing the shock absorption performance of landing gears, this paper proposes an optimization method for landing dynamics based on parameter sensitivity. Taking a specific aircraft landing gear as the object, its landing impact dynamics model was constructed. The Sobol global sensitivity analysis method was used to quantitatively evaluate how key shock absorber parameters—both structural and pneumatic-hydraulic—affect performance metrics such as ground loads and stroke. The results show that the oil chamber parameters—specifically the discharge coefficient, main orifice area, and pressurized oil area—have the greatest impact. Among these, the discharge coefficient has a total effect index as high as 56.67%. Based on this, the orifice area was selected as the optimization variable, with the goal of reducing the maximum landing vertical load. Considering engineering constraints such as stroke, a genetic algorithm was applied for optimization and verified through experiments. The optimized maximum vertical load was significantly reduced by 12.7%, effectively improving the shock absorption performance.

ABSTRACT This study evaluated the impacts of land and water management (LWM) intervention scenarios on runoff and sediment yield (SY) in Ethiopia's Bale Eco-Region (BER) under changing climate conditions. The scenarios analyzed include implementing conservation measures in non-cultivated lands (Scenario 1), cultivated lands (Scenario 2), and a combination of both (Scenario 3). These were compared against a Reference Scenario (i.e., no LWM interventions). The revised Soil and Water Assessment Tool (SWAT+) model was applied for baseline (1992–2020), and mid-century (2041–2070) and late-century (2071–2100) periods under SSP2-4.5 and SSP5-8.5 climate projections. Model calibration (2001–2009) and validation (1995–2000) for streamflow and sediment parameters confirmed SWAT+ suitability for the BER. Results indicate that, under the Reference Scenario, runoff and SY are projected rise by 12.8–53.7% and 16–60.6%, respectively, in future periods. Scenario 3, followed by Scenario 1, provided the greatest reductions in average areal runoff and SY. This study shows that conserving non-cultivated lands through LWM practices significantly reduces runoff and sediment yield. To effectively mitigate these impacts under changing climates, conservation should prioritize both cultivated and non-cultivated lands. The presented framework offers a transferable approach for evaluating LWM strategies in regions with comparable environmental conditions.

The dynamic response law of rigid pavement structures under varying aircraft movements was explored in this study. Virtual prototype models of the A320neo, A330−200 and A380−800 were developed using ADAMS/Aircraft software, which simulate scenarios of aircraft landing, turning and braking. A three-dimensional finite element model of rigid pavement, incorporating joint considerations, was subsequently established to analyze the response of the pavement structure under diverse aircraft loads. The findings indicate that the peak value of the landing impact load is generally lower than the maximum static wheel load, excluding rough landings. During aircraft turning, a pronounced partial load phenomenon is observed, with a maximum lateral force coefficient exceeding 0.50. In the braking phase, the longitudinal load may constitute 30−45% of the wheel's maximum static vertical load. Excluding rough landing scenarios, the peak bending tensile stress at the slab's bottom due to landing impact is lower than that under static wheel loading. During aircraft turning, lateral forces significantly amplify the interlayer friction shear stress. The partial load effect leads to a distinctly asymmetric distribution of bending tensile stress at the slab's bottom. Throughout the braking process, longitudinal forces increase both the interlayer friction shear stress and the bottom bending tensile stress.

Current passive anti-rollover systems exhibit inadequate adaptability to complex operational environments. Additionally, due to unidentified critical factors driving rollover incidents during landing, the design of active anti-tipping systems for airdrop remains constrained. Given the foregoing circumstances, this paper divides the landing impact process of the vehicle into the airbag cushioning stage and the rigid collision stage. In the airbag cushioning stage, a vertical impact test bench and a fluid–structure interaction (FSI) model is built up to obtain the terminal impact velocity when the airbag’s touching down speed is set as around 8 m/s. An oblique impact test bench and a dynamic model are proposed to investigate the influence of terminal sideslip angles and impact velocities on the vehicle’s roll/pitch stability during the rigid collision phase. Experimental and numerical analyses reveal that the peak overload during the airbag cushioning stage reaches approximately 11 g while the terminal impact velocity in this stage is around 2 m/s. In the rigid collision stage, higher initial descent velocities amplify the peak roll angles and significantly compromise the roll stability. Notably, adjusting the terminal sideslip angle from 90° to 0°/180° triples the critical horizontal velocity threshold from 5.3 m/s to 14.7 m/s which markedly enhances the vehicle’s stability. To address this, an active sideslip angle control system activated at a 250 m altitude is developed to align the vehicle’s horizontal velocity vector with its longitudinal axis to nearly 0°/180° and thus improves the roll/pitch stability. This study establishes a technical foundation for the design of a highly reliable anti-rollover device for the airdrop vehicle.

It is of great significance to explore the impacts of the spatiotemporal dynamic evolution of land use/landscape patterns on basin water quality. Based on the panel data and land use data from 78 national surface water quality monitoring stations in the Yellow River Basin from 2017 to 2023， the dynamic influences of human land use on water quality in the 78 sub-basins were investigated using the SWAT model， spatial Durbin model， and geographically weighted regression model. The study produced several significant results： ① The comprehensive index （CWQI） of water quality in the Yellow River Basin showed an increasing and then decreasing trend， and the overall water quality improved. Among the indices， pH， NH3-N （ionic state）， TN， and TP varied in the order of upstream &gt; downstream &gt; midstream， and the permanganate index varied as upstream &gt; midstream &gt; downstream. ② Arable land and construction land increased by 1.562×104 km2 and 1.176×104 km2， respectively， in the whole basin， spatial heterogeneity and diversity were low， and no serious landscape fragmentation occurred. ③ The effects of construction land， arable land， and landscape pattern on CWQI were spatially and temporally heterogeneous. There were negative spillover effects on CWQI from construction land， and positive spillover effects from arable land and SHDI. The positive impact of construction land on water quality was mainly concentrated in the downstream area. Positive impacts of arable land on water quality were mainly concentrated in the upstream and midstream areas. Increased diversity had a positive effect on water quality in only 24% of the sub-basins.

ABSTRACT Long-term temporal changes in land use and land cover (LULC) in the Awash basin have a substantial impact on groundwater resources through modifying the composition of water balance components. Therefore, in order to manage groundwater resources sustainably, an estimation of the spatial and temporal variation of annual recharge as a function of LULC was conducted in the Borkena sub-basin using a GIS-based WetSpass-M model. Meteorological and biophysical data in grid format and lookup tables were used to run the model. The automated digital filtering baseflow separation approach is used to independently compute recharge in order to calibrate and validate the model using streamflow data; consequently, its R2 and NSE for validation are 0.93 and 0.9, respectively. Using LULC maps from 1988 to 2019, the recharge was estimated to be 12.6% of the mean annual rainfall (1,279.2 mm) in 1988 and 10.7% of the mean annual rainfall (1,277.4 mm) in 2019. The study's findings are crucial for the sustainable management, planning, and utilization of groundwater resources.

Introduction: Proper soil management is essential for sustaining soil fertility and optimizing agricultural productivity. Understanding how soils respond to different land use practices is key to ensuring long-term land sustainability. Objective: This study evaluates the effects of various land use types on soil physicochemical properties in the North-Central Highlands of Ethiopia, establishing a baseline for future research and sustainable land management. Method: This study examined the impact of different land uses on soil fertility and quality by analyzing 108 composite soil samples across four land use types, three depths, and three slope positions, with triplicate sampling for accuracy. Key physicochemical properties were analyzed to assess soil physicochemical property and quality variations. Results: The study showed that cultivated land had significantly lower soil fertility than natural forestland, with lower levels of organic matter, nitrogen, phosphorous, exchangeable bases, and base saturation. Topsoil had a better nutrient content compared to subsoil, with higher levels of organic matter, nitrogen, phosphorous, potassium, and micronutrients. Moreover, soils on lower slopes had better chemical properties than those on upper slopes, with higher pH, exchangeable bases, and cation exchange capacity occurring at lower slopes. Conversion of natural forest to cropland led to significant (p &lt; 0.05) declines in organic matter, total nitrogen, and available phosphorus, highlighting severe soil degradation risks. These findings underscore the urgent need for improved land management practices and policy interventions to mitigate soil fertility loss. Conclusions: These findings will offer valuable information for policy makers, researchers and farmers to make well-informed decisions regarding land use planning and soil conservation strategies in the region. Further research is recommended to assess land use change impacts across various scales, from small sub-watersheds to regional and national levels, to support balanced agricultural development and ecosystem conservation.

Introduction: Jumping is a fundamental element of classical ballet, often performed with the feet turned out, in a position known as en dehors, achieved through hip external rotation. Experience level and impact attenuation strategies may play a crucial role in reducing injury risk during jump landings. This study aimed to investigate the impact during drop jump landings in en dehors versus parallel foot orientation in experienced ballet dancers. Method: Seventeen experienced ballet dancers (aged 18-31 years, with an average of 13 years of experience) and 15 controls (aged 20-32 years old) who were not dancers and did not engage in regular physical activity, participated in the study. Participants performed drop jumps from a 30 cm high block, landed on two force platforms, and immediately executed a maximum vertical jump with feet in en dehors position or parallel. Maximum vertical ground reaction force, time to reach this maximum, maximum rate of force development during drop landing, and maximum height of the jump performed immediately after drop landing were calculated and compared between groups and foot orientations. Results: Time to reach the maximum vertical ground reaction force was shorter in the en dehors compared to parallel foot orientation, with no significant group differences. Ballet dancers achieved higher vertical jumps after the drop landing compared to controls. Conclusions: Long-term classical ballet practice does not lead to lower impact landings in en dehors compared to parallel foot orientation. Ballet dancers may take more advantage of the impact and rebounding for performing the subsequent vertical jump.

Effect of carrier landing impact loads on the damping performance of turboprop engine vibration isolation systems

This study investigates the hydrological consequences of Land Use and Land Cover (LULC) transformations within the Sam Ngao Watershed (SNgW) from 2000 to 2020. Utilizing the Soil and Water Assessment Tool (SWAT), the research simulates watershed hydrological responses to observed LULC dynamics. To forecast future hydrological conditions, LULC scenarios for 2040 and 2060 were generated using a hybrid Cellular Automata-Markov Chain (CA-Markov) modeling approach. A hybrid classification methodology enhanced the accuracy of LULC mapping from Landsat imagery, integrating multiple classification techniques. Results reveal that LULC alterations between 2000 and 2020 significantly influenced the watershed’s hydrological regime, including declines in dry season flow (7.36%), groundwater discharge (25.43%), and evapotranspiration rates (7.63%), and increases in average annual streamflow (9.85%), wet season streamflow (12.85%), and surface runoff (33.21%). These shifts are primarily attributed to agricultural expansion and deforestation. Projected LULC changes for 2040–2060 indicate a potential reversal in trends, with increases in dry season flow, groundwater recharge, and evapotranspiration, accompanied by decreases in annual and wet season streamflow as well as surface runoff. Hydrological impacts were notably heterogeneous across sub-watersheds, reflecting the spatially uneven distribution of LULC changes. These findings offer valuable insights for decision-makers, water resource managers, and local stakeholders toward creating adaptive strategies for sustainable water resource management in the SNgW and analogous catchments. The study supports international efforts aligned with Sustainable Development Goal 6 (SDG 6) to secure universal access to clean water and sanitation through sustainable management, and with SDG 11 to create sustainable cities and communities through resilient infrastructure, inclusive urban planning, and climate-adaptive water management systems. The outcomes also provide a robust scientific foundation for researchers and policy developers engaged in hydrology, watershed management, and national land use planning frameworks.

This study aims to (1) analyze the impact of land and building use-right status on the obligation to pay Land and Building Tax (PBB) in the green belt area of Tuak Daun Merah Sub-district; and (2) examine the influence of use-right ownership on the level of community compliance with PBB payments. The research employed a qualitative descriptive approach through observation, interviews, and document analysis. The findings reveal that the lack of legal clarity regarding land status is the primary factor contributing to low tax compliance. Many residents do not possess use-right certificates despite residing on state-owned or green belt land, leading to legal uncertainty. Some residents continue to pay PBB without formal legal documentation as an attempt to secure potential future administrative legitimacy, while the majority refrain from paying taxes due to concerns over legal consequences or possible evictions. This condition directly affects the fluctuation of PBB revenue and reduces the effectiveness of local tax collection. Therefore, strategic governmental measures are required to reorganize land status, clarify ownership rights, and formulate fair and sustainable tax policies in order to enhance local revenue (PAD).

This literature review investigates the combined impacts of Land Use/Land Cover Change (LULCC) and climate change on natural hazards in tropical regions, emphasizing their relevance to Kinshasa. Using a thematic, narrative approach and 144 selected references, the study synthesizes global and regional findings on how urbanization, deforestation, and climate variability exacerbate hazards such as flooding, landslides, erosion, urban drought, and biodiversity loss. Key mechanisms include increased impervious surfaces, loss of natural buffers, hydrological disruption, and altered microclimates. In Kinshasa, these effects are amplified by fragile soils, steep topography, and rapid, unplanned urban growth. The study highlights how LULCC drives soil degradation, reduces groundwater recharge, and intensifies flash floods and urban heat islands. Concurrently, climate change increases extreme rainfall and drought risk, interacting with land cover changes to amplify vulnerability. The results show that Kinshasa’s environmental risks stem from both climatic forces and anthropogenic pressures, producing nonlinear, synergistic hazard dynamics. The review concludes that integrated, spatially explicit risk assessments are essential for informing adaptive urban planning and resilience strategies. It provides a conceptual foundation for modeling hazard interactions in Kinshasa and supports the development of targeted mitigation measures in rapidly urbanizing tropical cities.