A STUDY ON THE REPRESENTATIVE POINT OF HORSE’S CENTER OF GRAVITY

The purpose of this study was to explore are there bony landmarks on the horse body’s surface matching the motion of center of gravity. The relationship between the bony landmarks and the center of gravity during actual race under Buchner and Kubo horse inertial models were analyzed. Results showed Buchner and Kubo models had high consistency on the kinematic parameters of the center of gravity. Comparing the relationship of the middle of mesoscapula and tail root with the center of gravity in displacement, velocity and the absolute difference, it was found that the middle of mesoscapula under Kubo model is a suitable represent point of the center of gravity among the characteristic points of two models in the motion of observed race horses

Architecture of Heptagonal Metallo-macrocycles via Embedding Metal Nodes Into Its Rigid Backbone

Metal-organic macrocycles have received increasing attention not only due to their versatile applications such as molecular recognition, compounds encapsulation, anti-bacteria and others, but also for their important role in the study of structure-property relationship at nano scale. However, most of the constructions utilize benzene ring as the backbone, which restricts the ligand arm angle in the range of 60, 120 and 180 degrees. Thus, the topologies of most metallo-macrocycles are limited as triangles and hexagons, and explorations of using other backbones with large angles and the construction of metallo-macrocycles with more than six edges are very rare. In this study, we present a novel strategy for self-assembly two giant heptagonal metallo-macrocycles with an inner diameter of 5 nm, by embedding metal nodes into the ligand backbone and regulating the ligand arm angle. By complexing with metal ions, the angle between two arms at the 4,4” position of the central terpyridine (tpy) was extended, resulting in ring expansion of the metallo-macrocycle. This approach enabled the construction of giant and more complex metallo- macrocycles that could not be achieved with traditional benzene ring backbones. The characterization of complex molecules often requires the use of multiple techniques, such as multi-dimensional and multinuclear NMR and multidimensional mass spectrometry analysis. Here, we also utilized transmission electron microscopy (TEM) and ultra-high vacuum (∼E-10 torr) low-temperature (∼77 K) scanning tunneling microscopy (UHV-LT-STM) to characterize complex supramolecules. The resulting metallo-macrocycles formed hierarchical self-assembled nanotube structures at larger densities, which is observed by TEM, while UHV-LT-STM was used for direct visualization of individual complex supramolecules deposited on an Au(111) substrate. Our findings indicate that UHV-LT-STM is an effective methodology for characterizing supramolecules at a single molecule level, providing more details of the molecular structure that is difficult to resolve by the resolution of TEM.https://digitalcommons.odu.edu/gradposters2023_sciences/1005/thumbnail.jp

Numerical Simulation of a New Designed Mechanical Seals with Spiral Groove Structures

The spiral groove seal has a strong hydrodynamic effect, but it has poor pollution resistance at the seal’s end and has unfavorable sealing stability. Circumferential waviness seals can use the fluid to clean the surface and have a strong ability to self-rush, protecting the main cover from contamination. This study presents a novel wave-tilt-dam seal design that integrates spiral groove structures to enhance the hydrodynamic performance of circumferential waviness seals. The objective of the research is to evaluate the mechanical effectiveness of this new design through simulation modeling, with a focus on the impact of structural parameters such as rotational speed and seal pressure on the hydrodynamic behavior under various operating conditions. The results of the study indicate that the new structure effectively improves the hydrodynamic performance of the liquid seal, resulting in a significant increase in film rigidity. Additionally, the study identifies optimal values for structural parameters under specific conditions. By addressing the limitations of traditional spiral groove seals and improving their hydrodynamic performance, this research contributes to the advancement of seal technology