Theoretical Model for Mutual Radiation Resistance of Small Transducers at an Air‐Water Surface

1965 ◽  
Vol 37 (3) ◽  
pp. 532-533 ◽  
Author(s):  
Charles H. Sherman
Keyword(s):  
Theoretical Model ◽  
Radiation Resistance ◽  
Water Surface

scholarly journals Jumping dynamics of aquatic animals

2019 ◽  
Vol 16 (152) ◽  
pp. 20190014 ◽  
Author(s):  
Brian Chang ◽  
Jihye Myeong ◽  
Emmanuel Virot ◽  
Christophe Clanet ◽  
Ho-Young Kim ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Water Surface ◽  
The Body ◽  
Aquatic Animals ◽  
Physical Constraints ◽  
Physical Conditions ◽  
Fast Motion ◽  
Taxonomic Groups ◽  
Axisymmetric Bodies ◽  
Flapping Mechanism

Jumping out of water is a phenomenon exhibited by a variety of aquatic and semi-aquatic animals. Yet, there is no common groundwork that clarifies the physical constraints required to jump out of water. In this study, we elucidate the physical conditions required for an animal to jump out of water. More than 100 jumps are analysed over five taxonomic groups. By balancing the power produced by animals with drag-induced dissipation, we expect that maximum jumping height, H , scales with body length, L , as H / L ∼ L −1/3 ∼ Fr 2 , where the Froude number, Fr, is a ratio of inertia to gravity. To identify jumping regimes, simplified experiments are conducted by shooting axisymmetric bodies through the water surface. Here, we see a transition in which partial exits scale as H / L ∼ Fr and complete exits scale as H / L ∼ Fr 2 . A bioinspired robotic flapping mechanism was designed to mimic the fast motion of impulsive jumping animals. When exiting water, the robot carries a large volume of fluid referred to as an entrained mass. A theoretical model is developed to predict the jumping height of various water-exiting bodies, which shows that the mass of the entrained fluid relative to the mass of the body limits the maximum jumping height. We conclude that the lack of entrained fluid allows animals to reach extraordinary heights compared to our water-exiting robots.

scholarly journals Effect of Anderson Localization on Auger Destruction of DNA

2012 ◽  
Vol 2012 ◽  
pp. 1-3
Author(s):  
N. N. Turaeva ◽  
S. Schroeder ◽  
B. L. Oksengendler
Keyword(s):  
Theoretical Model ◽  
Radiation Resistance ◽  
Anderson Localization ◽  
Localized States ◽  
Cascade Process ◽  
Electron States ◽  
Delocalized Electron

The effect of Anderson localization in DNA on the Auger destruction by the Coulombic explosion at ionized radiation has been theoretically discussed in the present work. The theory of Auger destruction of DNA has been modified taking into account the localized and delocalized electron states in DNA owing to the correlated disorder in a sequence of nucleotides. According to the modified theoretical model of Auger destruction, the dominant ratio of delocalized states to localized states in exon compared to intron results in stronger radiation resistance of exons to ionized irradiation causing the Auger-cascade process than the radiation resistance of introns.

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