Results 31 to 40 of about 197,944 (293)
Air Pressure and Coefficient of Restitution of a Ball [PDF]
Journal of Science International School Bangkok, 2013 The relationship between the pressure of a ball and its coefficient of restitution was investigated, a rubber handball was inflated to eight varying air pressures and then dropped from a constant height.
JuWon Kim, Chanhyeok Yim
doaj +2 more sources
Nonperturbative analysis of the evolution of cosmological perturbations through a nonsingular bounce
, 2013 In bouncing cosmology, the primordial fluctuations are generated in a cosmic contraction phase before the bounce into the current expansion phase.
Garfinkle, David +3 more
core +1 more source
International Journal of Modern Physics A, 2009 We investigate if theories yielding bouncing cosmological models also generate wormhole solutions. We show that two of them present sensible traversable static wormhole solutions, while for the third possibility such solutions are absent.
Pinto-Neto, N. +2 more
openaire +3 more sources
Comment on "Quantum bounce and cosmic recall" [arXiv:0710.4543]
, 2008 A recently derived inequality on volume fluctuations of a bouncing cosmology, valid for states which are semiclassical long after the bounce, does not restrict pre-bounce fluctuations sufficiently strongly to conclude that the pre-bounce state was ...
Bojowald, Martin
core +1 more source
Physical Review D, 2014 We report on the possibility to use dark matter particle's mass and its cross section as a smoking gun signal of the existence of a Big Bounce at the early stage in the evolution of our currently observed universe. A model independent study of dark matter production in the pre-bounce contraction and the post-bounce expansion epochs of the bounce ...
Li, Changhong +2 more
openaire +2 more sources
Coefficient of Restitution of Wet Tennis Balls [PDF]
International Scholastic Journal of Science, 2014 The coefficient of restitution of a damp tennis ball is of interest to tennis players. Using a spray bottle, water was added to a tennis ball and the mass of water on the wet ball was determined. The ball was then dropped from a fixed height of 0.86 m.
Eugene Jang, Tony Kim
doaj +1 more source
Pre-Big-Bang Black-Hole Remnants and Past Low Entropy
Universe, 2018 Dark matter could be composed by black-hole remnants formed before the big-bang era in a bouncing cosmology. This hypothetical scenario has implications on the issue of the arrow of time: it upsets a common attribution of past low entropy to the state of
Carlo Rovelli, Francesca Vidotto
doaj +1 more source
Primordial gravitational waves spectrum in the Coupled-Scalar-Tachyon Bounce Universe
European Physical Journal C: Particles and Fields, 2020 We extend our study on the Coupled-Scalar-Tachyon Bounce Universe to obtain its gravitational waves spectrum. We derive in detail the equations of motion for the tensorial modes of primordial metric perturbations in the Coupled-Scalar-Tachyon Bounce ...
Nan Zhang, Yeuk-Kwan E. Cheung
doaj +1 more source
Dynamics Test Research of Bounce of Carrier-Based Aircraft Arresting Hook
Applied Sciences, 2020 The test of arresting hook bounce is one of the most essential technologies in the design and research of arresting hook. In order to research the dynamic performance of the hook after touchdown and impacting with the deck when the aircraft is arrested ...
Yiming Peng +3 more
doaj +1 more source
Psychosocial Outcomes in Patients With Endocrine Tumor Syndromes: A Systematic Review
Pediatric Blood &Cancer, EarlyView.ABSTRACT Introduction The combination of disease manifestations, the familial burden, and varying penetrance of endocrine tumor syndromes (ETSs) is unique. This review aimed to portray and summarize available data on psychosocial outcomes in patients with ETSs and explore gaps and opportunities for future research and care.
Daniël Zwerus +6 more
wiley +1 more source