Due to their extensive use in various applications, helicopters need be able land a variety of conditions. Typically, helicopter landing gear system with skids or passive wheel-dampers is designed based on only one critical touchdown condition. Thus, this may not perform well different A magnetorheological (MR) dampers would promising candidate solve problem. However, semi-active controller mus...

CONTEXT Researchers have suggested that large landing forces, excessive quadriceps activity, and an erect posture during landing are risk factors for anterior cruciate ligament (ACL) injury. The influence of knee kinematics on these risk factors has been investigated extensively, but trunk positioning has received little attention. OBJECTIVE To determine the effect of trunk flexion on landing...

The purpose of this study was to determine the differences of kinematics, impact force, soft-tissue vibration, and muscle activity between active (AL) and unexpected landing (UL). Twelve trained male volunteers were requested to land from self-made elevated platform at three heights (30, 45, and 60cm) in AL and UL conditions. During active landing, human body can adjust the landing strategy of ...

This study examined trends along a gradient of fishing intensity in an artisanal coral reef fishery over a 10-year period along 75 km of Kenya's most populated coastline. As predicted by Malthusian scenarios, catch per unit effort (CPUE), mean trophic level, the functional diversity of fished taxa, and the diversity of gear declined, while total annual catch and catch variability increased alon...

objective(s): the effect of silica nanoparticles (snps) in sport shoes outsoles on the  parameters related to anterior cruciate ligament (acl) injury has not been investigated. the aim of this study was to investigate the effect of shoes outsole containing a composite of thermoplastic elastomer based on styrene-butadiene and silica nanoparticles (tpen shoe) on knee valgus angle (kva) as a risk ...

In the multi-gear coastal fleet in Algarve (South Portugal), fishers own licenses for various fishing gears. However, they generally do not use all these licenses, and therefore, it is difficult to estimate impacts this has on local environment. study, two types of questionnaires were used directed from during interviews carried out between November 2019 July 2021 with objective validate métier...

Autonomous landing is a challenging but important task for Unmanned Aerial Vehicles (UAV) to achieve high level of autonomy. The fundamental requirement for landing is the knowledge of the height above the ground, and a properly designed controller to govern the process. This paper presents our research results in the study of landing an autonomous helicopter. The above‐the‐ground hei...

Background: The purpose of the present study was to investigate correlative and predictive relationship of lower extremity anatomical alignment, isometric hip abduction and external rotation strength with jump-landing biomechanics using Landing Error Scoring System (LESS). Methods: Anatomical alignment and isometric lower extremity muscle strength of 30 active...