scholarly journals Cosmic Gas Thermodynamics at z = 1089

2021 ◽  
Author(s):  
Martin Reid Johnson
Keyword(s):  
Kinetic Energy ◽  
Energy Loss ◽  
Ideal Gas ◽  
Λcdm Model ◽  
Universal Expansion ◽  
The Universe ◽  
Kinetic Energy Loss

Abstract The Universe at z = 1089 is treated as an expanding ideal gas. Its internal kinetic energy loss exceeds the amount absorbed by gravity and drives further expansion. A Hubble relation (Hg) is derived and compared to the value found by the ΛCDM model (HΛ) over the range z = 1089 to 0. The results suggest that the adiabatic release of energy from cosmic gas accounts for about half of present-day Universal expansion.

scholarly journals Tortuosity and the Averaging of Microvelocity Fields in Poroelasticity

2013 ◽  
Vol 80 (2) ◽  
Author(s):  
M. F. Souzanchi ◽  
L. Cardoso ◽  
S. C. Cowin
Keyword(s):  
Porous Media ◽  
Kinetic Energy ◽  
Energy Loss ◽  
Cancellous Bone ◽  
Quantitative Measure ◽  
Pore Fluid ◽  
Fluid Viscosity ◽  
Anisotropic Porous Media ◽  
Pore Architecture ◽  
Kinetic Energy Loss

The relationship between the macro- and microvelocity fields in a poroelastic representative volume element (RVE) has not being fully investigated. This relationship is considered to be a function of the tortuosity: a quantitative measure of the effect of the deviation of the pore fluid streamlines from straight (not tortuous) paths in fluid-saturated porous media. There are different expressions for tortuosity based on the deviation from straight pores, harmonic wave excitation, or from a kinetic energy loss analysis. The objective of the work presented is to determine the best expression for tortuosity of a multiply interconnected open pore architecture in an anisotropic porous media. The procedures for averaging the pore microvelocity over the RVE of poroelastic media by Coussy and by Biot were reviewed as part of this study, and the significant connection between these two procedures was established. Success was achieved in identifying the Coussy kinetic energy loss in the pore fluid approach as the most attractive expression for the tortuosity of porous media based on pore fluid viscosity, porosity, and the pore architecture. The fabric tensor, a 3D measure of the architecture of pore structure, was introduced in the expression of the tortuosity tensor for anisotropic porous media. Practical considerations for the measurement of the key parameters in the models of Coussy and Biot are discussed. In this study, we used cancellous bone as an example of interconnected pores and as a motivator for this study, but the results achieved are much more general and have a far broader application than just to cancellous bone.

scholarly journals Numerical modelling of transonic centripetal flow in radial turbine blade cascade

2018 ◽  
Vol 168 ◽  
pp. 02008
Author(s):  
Petr Straka
Keyword(s):  
Experimental Data ◽  
Kinetic Energy ◽  
Numerical Modelling ◽  
Energy Loss ◽  
Linear Representation ◽  
Buffer Zone ◽  
Blade Cascade ◽  
Radial Turbine ◽  
Paper Method ◽  
Kinetic Energy Loss

Numerical modelling of transonic centripetal turbulent flow in radial blade cascade is described in this paper. Method of the confusor buffer zone is applied to overcome some numerical obstacles related with specifical properties of the outlet confusor. Kinetic energy loss coeficient of the radial blade cascade is compared with its linear representation and with experimental data.

scholarly journals Motions of the running horse and cheetah revisited: fundamental mechanics of the transverse and rotary gallop

2008 ◽  
Vol 6 (35) ◽  
pp. 549-559 ◽  
Author(s):  
John E.A. Bertram ◽  
Anne Gutmann
Keyword(s):  
Kinetic Energy ◽  
Energy Loss ◽  
Water Surface ◽  
Fundamental Difference ◽  
Centre Of Mass ◽  
Transition Strategies ◽  
Kinetic Energy Loss

Mammals use two distinct gallops referred to as the transverse (where landing and take-off are contralateral) and rotary (where landing and take-off are ipsilateral). These two gallops are used by a variety of mammals, but the transverse gallop is epitomized by the horse and the rotary gallop by the cheetah. In this paper, we argue that the fundamental difference between these gaits is determined by which set of limbs, fore or hind, initiates the transition of the centre of mass from a downward–forward to upward–forward trajectory that occurs between the main ballistic (non-contact) portions of the stride when the animal makes contact with the ground. The impulse-mediated directional transition is a key feature of locomotion on limbs and is one of the major sources of momentum and kinetic energy loss, and a main reason why active work must be added to maintain speed in locomotion. Our analysis shows that the equine gallop transition is initiated by a hindlimb contact and occurs in a manner in some ways analogous to the skipping of a stone on a water surface. By contrast, the cheetah gallop transition is initiated by a forelimb contact, and the mechanics appear to have much in common with the human bipedal run. Many mammals use both types of gallop, and the transition strategies that we describe form points on a continuum linked even to functionally symmetrical running gaits such as the tölt and amble.

Coefficient of restitution and kinetic energy loss of rockfall impacts

2015 ◽  
Vol 20 (6) ◽  
pp. 2297-2307 ◽  
Author(s):  
Li-ping Li ◽  
Shang-qu Sun ◽  
Shu-cai Li ◽  
Qian-qing Zhang ◽  
Cong Hu ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Energy Loss ◽  
Coefficient Of Restitution ◽  
Kinetic Energy Loss

scholarly journals Measurements of Kinetic Energy Loss for Particles Impacting Surfaces

1990 ◽  
Vol 12 (4) ◽  
pp. 926-946 ◽  
Author(s):  
Stephen Wall ◽  
Walter John ◽  
Hwa-Chi Wang ◽  
Simon L. Goren
Keyword(s):  
Kinetic Energy ◽  
Energy Loss ◽  
Kinetic Energy Loss

Kinetic energy loss and convective acceleration in respiratory resistance measurements

Lung ◽  
1979 ◽  
Vol 156 (1) ◽  
pp. 33-42 ◽  
Author(s):  
S. H. Loring ◽  
E. A. Elliott ◽  
J. M. Drazen
Keyword(s):  
Kinetic Energy ◽  
Energy Loss ◽  
Respiratory Resistance ◽  
Kinetic Energy Loss
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