Motion in General Elliptic Orbit with Respect to a Dragging and Precessing Coordinate Frame

In this paper, we proposed a new device for geometry errors measurement and coaxiality evaluation, and the corresponding methodology for coaxiality evaluation from measurement data is presented, which allows to characterize multiple holes at a time. Unlike traditional measurement system a laser sensor is mounted onto out of the holes so that multi-hole surfaces can be “seen” by the senor when it rotates around a fixed axis. First the intersections (or ellipse profiles) of the sensor’s scanning plane and holes, are computed by fitting. Then, the center coordinates and profile points of the ellipse are computed and transformed to the 3D global coordinate frame. Finally the centerline of the hole is determined from the 3D profile points by using a weighted least-squares fitting algorithm. In addition, to reduce the effect of noises on the measurement result, error analysis and compensation techniques are studied to improve the measurement accuracy. A case study is presented to validate the measurement principle and data processing approach.

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On the Stability of a Tethered System with a Free End in Elliptic Orbit

The Journal of the Astronautical Sciences ◽

10.1007/bf03546320 ◽

2001 ◽

Vol 49 (2) ◽

pp. 237-253

Author(s):

M. Ruiz ◽

J. Peláez ◽

E. C. Lorenzini

Keyword(s):

Elliptic Orbit ◽

The Stability

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Tentative Peptide‒Lipid Bilayer Models Elucidating Molecular Behaviors and Interactions Driving Passive Cellular Uptake of Collagen-Derived Small Peptides

Molecules ◽

10.3390/molecules26030710 ◽

2021 ◽

Vol 26 (3) ◽

pp. 710

Author(s):

Pathomwat Wongrattanakamon ◽

Wipawadee Yooin ◽

Busaban Sirithunyalug ◽

Piyarat Nimmanpipug ◽

Supat Jiranusornkul

Keyword(s):

Lipid Bilayer ◽

Lipid Bilayers ◽

Mean Square Displacement ◽

Dynamics Simulation ◽

Coordinate Frame ◽

Mean Square ◽

Binding Modes ◽

Small Peptides ◽

Collagen Peptides ◽

Electron Density Profiles

Collagen contains hydroxyproline (Hyp), which is a unique amino acid. Three collagen-derived small peptides (Gly-Pro-Hyp, Pro-Hyp, and Gly-Hyp) interacting across a lipid bilayer (POPC model membrane) for cellular uptakes of these collagen-derived small peptides were studied using accelerated molecular dynamics simulation. The ligands were investigated for their binding modes, hydrogen bonds in each coordinate frame, and mean square displacement (MSD) in the Z direction. The lipid bilayers were evaluated for mass and electron density profiles of the lipid molecules, surface area of the head groups, and root mean square deviation (RMSD). The simulation results show that hydrogen bonding between the small collagen peptides and plasma membrane plays a significant role in their internalization. The translocation of the small collagen peptides across the cell membranes was shown. Pro-Hyp laterally condensed the membrane, resulting in an increase in the bilayer thickness and rigidity. Perception regarding molecular behaviors of collagen-derived peptides within the cell membrane, including their interactions, provides the novel design of specific bioactive collagen peptides for their applications.

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