This study investigates the impact of extreme rainfall events on soil erosion in the downstream Parnaíba River Basin, located in the Brazilian Cerrado. The analysis focused on rainfall erosivity (R factor) and soil erodibility (K factor) as key indicators. The average erosivity in the region was 9051 MJ mm h−1ha−1year−1, with a variation between 7943 and 10,081 MJ mm h−1ha−1year−1, suggesting a high erosive potential, mainly in the rainiest months, from December to April. The soils of the studied area, mainly Ultisols and Chernosols, present high to very high erodibility, with K factor values ranging from 0.025 to 0.050 t h MJ−1 mm−1. Furthermore, fieldwork revealed areas, near highways, with apparently fragile soils, as well as rills and gullies, identified through photographs taken during fieldwork. These locations, due to the combination of high erosivity and susceptible soils, were considered prone to the occurrence of erosion processes, representing an additional risk to local infrastructure. The spatialization of R and K factors, along with field observations, showed that much of the area is at high risk of erosion and landslides, particularly in regions with greater topographic variability and proximity to water bodies. These results provide a basis for the development of mitigation strategies, being important for the effective prevention of landslides.
In older adults with disabilities, muscle weakness reduces mobility and causes postural issues. Electrical muscle stimulation (EMS) training is effective for increasing strength by inducing involuntary skeletal muscle contractions. Thus, this study aimed to examine changes in lumbar movement, muscle activity during walking, and maximum muscle strength of lower-limb joints based on an 8-week EMS exercise program for older adults with physical disabilities. Sixteen older adults (aged 56–78 years) with physical disabilities were selected and randomly assigned to either the exercise group (EG, n = 8) or the control group (CG, n = 8). EG participants were instructed to wear EMS suits and participate in an elastic band and bare-body exercise program, whereas CG participants performed the exercise program without the EMS suits. Lumbar range of motion (ROM), body circumference, partial volume, maximum muscle strength, and muscle activity were measured. Statistical analysis was performed using SPSS 28.0 for Windows, with the critical value of α = 0.05. Compared to CG participants, EG participants had a superior ROM, body volume, partial volume, maximum muscle strength (knee joints), and muscle activity while walking. These positive outcomes highlight the efficacy of combining EMS with an exercise program for strength and rehabilitation training in older adults with physical disabilities.
Proposed herein is an environment-friendly method to realize oil/water separation. Nylon mesh is exposed to atmospheric pressure plasma for surface modification, by which micro/nano structures and oxygen-containing groups are created on nylon fibers. Consequently, the functionalized mesh possesses superhydrophilicity in air and thus superoleophobicity underwater. The water pre-wetted mesh is then used to separate oil/water mixtures with the separation efficiency above 97.5% for various oil/water mixtures. Results also demonstrate that the functionalized nylon mesh has excellent recyclability and durability in terms of oil/water separation. Additionally, polyurethane sponge slice and polyester fabric are also functionalized and employed to separate oil/water mixtures efficiently, demonstrating the wide suitability of this method. This simple, green and highly efficient method overcomes a nontrivial hurdle for environmentally-safe separation of oil/water mixtures, and offers insights into the design of advanced materials for practical oil/water separation.
This study examines the impact of state highway construction contracts on state spending efficiency controlling for production structure, service demands, and situational factors. The theoretical argument is that because highway construction projects are relatively large in scale, complex, and can be monitored through objective performance measurement, state highway construction programs may save government production costs through contracts. Contracting helps highway producers achieve efficiency by optimizing production size based on workload and task complexity. The unit of analysis is 48 state governments’ highway construction contracts from 1998 to 2008. Through a two-stage analysis method including a Total Function Productivity (TFP) index and system dynamic panel data analysis, the results suggest that highway construction contracts enhance state highway spending efficiency, especially for large-scale construction projects.
The recession cone and recession function are very important research objects in Convex Analysis. They have extensive applications in the optimization theory. Firstly, we study the properties of the recession cone and recession function. The positive homogeneity and subadditivity of recession function are mainly discussed. And the different methods are considered to prove these properties. Secondly, we discuss the unboundedness of the convex sets and convex functions by using recession cone and recession function.
Maintaining balance is essential for daily activities; deficits in hearing-impaired adolescents can severely impact their academics and daily life. Suspension training is employed to enhance the coordination of multiple muscle groups within the body and ultimately to improve balance. A total of 105 students with non-genetic hearing impairments, comprising 65 boys and 40 girls, participated in the study. Balance training using the TRS suspension belt included exercises such as prone elbow brace, supine back brace, kneeling elbow brace, lateral elbow brace, prone hip flexion, and supine hip lift. Strength training using equipment involved exercises like single-leg suspension squat, flying bird brace, supine suspension arm flexion, seated static brace, and standing butterfly pinch chest. The main outcome measures included static balance tests (lambda footwork, Wolfson postural stress test), dynamic balance tests (functional forward reach test, balance beam walk test), and vestibule function tests (rotation-walk test). The results of the lambda footwork and Wolfson postural stress tests revealed highly significant differences between 8 weeks and 16 weeks of intervention (p < 0.01). The Functional Forward Stretch test demonstrated a significant difference between 8 weeks of intervention and 2 weeks of intervention at 16 weeks (p < 0.05). The balance beam walking test indicated a significant improvement at 8 weeks (p < 0.05) and a highly significant improvement at 16 weeks (p < 0.01). In the spin-walk test, no statistically significant differences were observed between the pre-experimental test, the 8-week intervention, and the 16-week intervention (p > 0.05). Leveraging the expropriation system to mediate skeletal muscle movement and muscle contraction coordination can improve balance. Suspension training significantly improved balance during activities requiring static non-interference maintenance. However, suspension training did not demonstrate a significant effect on improving vestibule function. Overall, suspension training was effective in enhancing balance in all patients with non-hereditary deafness.
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