Sport specific assessment of inter-limb asymmetries: A way to reduce injuries
In recent years, lower inter-limb asymmetries have become a topic of increasing interest in sports research. Numerous studies have investigated the occurrence of between-limb differences in a variety of physical tests, ranging from strength, sprinting, and change of direction speed to jumping tasks. The main focus has been the association of asymmetries to either enhanced injury risk or reduced physical performance. Sport specific aspects and differences of lower limb asymmetries have not often been analysed. Additionally, most studies have been performed with male athletes. Women, however, present higher prevalence of lower limb asymmetries in strength, coordination, and postural control than men. These two aspects were therefore addressed in the present study. Female youth soccer (n=18, age: 16.7 ± 0.8 years) and floorball (n=18, age: 17.6 ± 0.9 years) players completed a test battery consisting of six unilateral jumping tasks in horizontal and lateral direction to detect sport specificity in inter-limb asymmetries. The test comprised the following hops: (1) Single Leg Hop for Distance and (2) a newly created version of it, (3) Single Leg Triple Hop, (4) Single Leg Crossover Hop, (5) Side Hop and (6) Single Leg 6-meters Timed Hop. The scores of every jump were calculated into Limb Symmetry Indexes for each participant. A linear mixed effect (LME) model (using function lmer in program R) was applied to evaluate the effects of sport and jump type on asymmetries. In terms of the whole test battery, there was a significantly higher magnitude of asymmetries in soccer compared to floorball (p=0.0067) with a mean difference of 1.9%. Three significant differences between the effects of different jump types were detected (5>2: p=0.027; 5>3: p6: p=0.014). Moreover, the results showed no significant effect on leg dominance. According to the findings of this study, soccer appears to be more asymmetric than floorball, leading to the suggestion that inter-limb asymmetries may not only be task-specific, but also sportspecific. Since no significant correlations were detected, this study suggests that inter-limb asymmetries are independent of leg dominance. Considering the possible reduction in athletic performance and increasing injury risk, strength and conditioning coaches are advised to assess athletes' inter-limb asymmetries using a broad, sport specific test battery and decrease them.
Inclined Sedimentation of Suspensions: Theoretical and Experimental Investigation into the Boycott Effect
The Boycott Effect is a phenomenon where sedimentation rate can be increased by tilting the container which holds the suspension, making it a way to increase the efficiency of the process without additional energy input. This makes the Boycott Effect valuable in speeding up and optimising a multitude of industrial applications such as wastewater management and food processing, all of which employ sedimentation to separate particulate matter from the fluids in which they are suspended in. Thus, it is imperative to model the Boycott Effect accurately for a wide range of cases, including arbitrary shaped containers and suspensions of various concentrations without the need to run costly, computationally expensive numerical simulations. In this project I investigated the inclined sedimentation of suspensions both theoretically and experimentally. Experimentally, two image tracking programs were created and tested out on my own experimental videos. I demonstrated the use of a novel method for making use of the Beer-Lambert Law to optically keep track of local concentration of suspensions. This method allows more information to be gathered about the sedimentation process in a very low-cost, non-equipment intensive or invasive way. Theoretically, I expanded upon the well-known analytical 2D PNK theory by accounting for concentration-hindering and sediment build-up effects, as well as the geometrical theory for 3D cylindrical geometries. All parts of the theoretical model were verified with experimental data and shown to have good agreement. (233 words)
Design of a new Hydrogen Fueled Hybrid Car Prototype
The proposed project involves a new water-fueled hybrid car prototype that integrates various technologies, including photovoltaic (PV) panels, electrolysis, a fuel cell, a metal hydride tank, and a battery. The car is equipped with PV panels on its surface, such as the roof or hood, which convert solar energy into electricity. This electricity powers a DC motor that propels the vehicle. Excess electricity can be stored in a battery or used in an electrolysis system to split water into hydrogen and oxygen. The hydrogen is stored in a metal hydride tank for later use. Metal hydrides are materials capable of absorbing and releasing hydrogen gas, providing a safe and compact storage solution. The fuel cell converts hydrogen into electricity to power the DC motor when sunlight is not available. This hybrid system allows for direct solar-powered operation while also storing excess energy as hydrogen. Experimental tests were conducted on a prototype of this water-fueled car, with the fuel cell serving as a backup power source to ensure continuous operation even without solar energy. This concept offers several advantages, including the use of renewable solar energy, zero emissions during fuel cell operation, and the ability to store and utilize excess energy.