scholarly journals An Evolution Based on Various Energy Strategies

Entropy ◽  
2021 ◽  
Vol 23 (3) ◽  
pp. 317
Author(s):  
Alexander O. Gusev ◽  
Leonid M. Martyushev
Keyword(s):  
Energy Dissipation ◽  
Total Energy ◽  
Entropy Production ◽  
Basic Principles ◽  
Specific Strategy ◽  
Interesting Connection ◽  
Simulation Results ◽  
Energy Strategies ◽  
Selection Of ◽  
Total Energy Dissipation

The simplest model of the evolution of agents with different energy strategies is considered. The model is based on the most general thermodynamic ideas and includes the procedures for selection, inheritance, and variability. The problem of finding a universal strategy (principle) as a selection of possible competing strategies is solved. It is shown that when there is non-equilibrium between the medium and agents, a direction in the evolution of agents arises, but at the same time, depending on the conditions of the evolution, different strategies can be successful. However, for this case, the simulation results reveal that in the presence of significant competition of agents, the strategy that has the maximum total energy dissipation of agents arising as a result of evolution turns out to be successful. Thus, it is not the specific strategy that is universal, but the maximization of dissipation. This result discovers an interesting connection between the basic principles of Darwin–Wallace evolution and the maximum entropy production principle.

Use of a stacked drop manhole for energy dissipation: a case study in Edmonton, Alberta

2009 ◽  
Vol 36 (6) ◽  
pp. 1037-1050 ◽  
Author(s):  
G. Adriana Camino ◽  
David Z. Zhu ◽  
Nallamuthu Rajaratnam ◽  
Manas Shome
Keyword(s):  
Energy Dissipation ◽  
Total Energy ◽  
Laboratory Investigation ◽  
Flow Regimes ◽  
Flow Patterns ◽  
The Other ◽  
Inflow Conditions ◽  
Water Depths ◽  
Total Energy Dissipation

This paper reports on a laboratory investigation into the performance of a novel stacked drop manhole design where two identical rectangular manholes are stacked one beside the other but at different heights so that there is a drop in elevation from one to the other. The focus of the study was to estimate the energy dissipation that occurs in such stacked manholes during diverse inflow conditions. Flow regimes inside the structure were identified and the effectiveness of the design was assessed under variable inflow conditions. Total energy dissipation in the stacked manhole was found to range from about 50% to 90%, and the contribution of each manhole chamber to the overall energy dissipation was assessed. A relationship between water depths in the manhole chambers and the corresponding outflow conditions was established. In addition, an analysis of the flow patterns and flow regimes highlighted the relevant parameters involved in the mechanisms of energy dissipation.

scholarly journals Estimating Energy Dissipation Rate from Breaking Waves Using Polarimetric SAR Images

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6540
Author(s):  
Rafael D. Viana ◽  
João A. Lorenzzetti ◽  
Jonas T. Carvalho ◽  
Ferdinando Nunziata
Keyword(s):  
Energy Dissipation ◽  
Total Energy ◽  
Dissipation Rate ◽  
Temporal Distribution ◽  
Wave Model ◽  
Breaking Waves ◽  
Fast Response ◽  
Energy Dissipation Rate ◽  
Sar Data ◽  
Total Energy Dissipation

The total energy dissipation rate on the ocean surface, ϵt (W m−2), provides a first-order estimation of the kinetic energy input rate at the ocean–atmosphere interface. Studies on the spatial and temporal distribution of the energy dissipation rate are important for the improvement of climate and wave models. Traditional oceanographic research normally uses remote measurements (airborne and platforms sensors) and in situ data acquisition to estimate ϵt; however, those methods cover small areas over time and are difficult to reproduce especially in the open oceans. Satellite remote sensing has proven the potential to estimate some parameters related to breaking waves on a synoptic scale, including the energy dissipation rate. In this paper, we use polarimetric Synthetic Aperture Radar (SAR) data to estimate ϵt under different wind and sea conditions. The used methodology consisted of decomposing the backscatter SAR return in terms of two contributions: a polarized contribution, associated with the fast response of the local wind (Bragg backscattering), and a non-polarized (NP) contribution, associated with wave breaking (Non-Bragg backscattering). Wind and wave parameters were estimated from the NP contribution and used to calculate ϵt from a parametric model dependent of these parameters. The results were analyzed using wave model outputs (WAVEWATCH III) and previous measurements documented in the literature. For the prevailing wind seas conditions, the ϵt estimated from pol-SAR data showed good agreement with dissipation associated with breaking waves when compared to numerical simulations. Under prevailing swell conditions, the total energy dissipation rate was higher than expected. The methodology adopted proved to be satisfactory to estimate the total energy dissipation rate for light to moderate wind conditions (winds below 10 m s−1), an environmental condition for which the current SAR polarimetric methods do not estimate ϵt properly.

Effect of Roughness on Frictional Energy Dissipation in Presliding Contacts

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Deepak B. Patil ◽  
Melih Eriten
Keyword(s):  
Energy Dissipation ◽  
Total Energy ◽  
Rough Surface ◽  
Power Law ◽  
Roughness Parameters ◽  
Frictional Energy ◽  
Real Area Of Contact ◽  
Frictional Energy Dissipation ◽  
Total Energy Dissipation ◽  
Real Area

A finite element model (FEM) is used to investigate the effect of roughness on the frictional energy dissipation for an elastic contact subjected to simultaneous normal and tangential oscillations. Frictional energy losses are correlated against the maximum tangential load as a power-law where the exponents show the degree of nonlinearity. Individual asperity is shown to undergo similar stick–slip cycles during a loading period. Taller asperities are found to contribute significantly to the total energy dissipation and dominate the trends in the total energy dissipation. The authors' observations for spherical contacts are extended to the rough surface contact, which shows that power-law exponent depends on stick durations individual asperity contacts experience. A theoretical model for energy dissipation is then validated with the FEM, for both spherical and rough surface contacts. The model is used to study the influence of roughness parameters (asperity density, height distribution, and fractal dimension) on magnitude of energy dissipation and power-law exponents. Roughness parameters do not influence the power-law exponents. For a phase difference of π/2 between normal and tangential oscillations, the frictional energy dissipation shows quadratic dependence on the tangential fluctuation amplitude, irrespective of the roughness parameters. The magnitude of energy dissipation is governed by the real area of contact and, hence, depends on the surface roughness parameters. Larger real area of contact results in more energy under similar loading conditions.

States of minimum dissipation in magnetohydrodynamics: a review

1996 ◽  
Vol 56 (3) ◽  
pp. 531-551 ◽  
Author(s):  
Lee Phillips
Keyword(s):  
Fluid Dynamics ◽  
Energy Dissipation ◽  
Boundary Conditions ◽  
Total Energy ◽  
Recent Literature ◽  
Steady States ◽  
Current State ◽  
State Of Research ◽  
Total Energy Dissipation

The hypothesis that the steady, or statistically steady, states of a magnetofluid can be predicted by minimizing the integral of the total energy dissipation is discussed in relation to theorems in fluid dynamics. A survey is made of the recent literature wherein the hypothesis is used to predict magnetofluid behaviour and some related work. A detailed discussion of boundary conditions is provided, and we close with a brief summary of the current state of research.

scholarly journals Recrystallization and damage of ice in winter sports

2017 ◽  
Vol 375 (2086) ◽  
pp. 20150353 ◽  
Author(s):  
Alexandra Seymour-Pierce ◽  
Ben Lishman ◽  
Peter Sammonds
Keyword(s):  
Energy Dissipation ◽  
Total Energy ◽  
Polarized Light ◽  
Experimental Results ◽  
Winter Sports ◽  
Thin Sections ◽  
Winter Sport ◽  
Show Evidence ◽  
Earthquake Faults ◽  
Total Energy Dissipation

Ice samples, after sliding against a steel runner, show evidence of recrystallization and microcracking under the runner, as well as macroscopic cracking throughout the ice. The experiments that produced these ice samples are designed to be analogous to sliding in the winter sport of skeleton. Changes in the ice fabric are shown using thick and thin sections under both diffuse and polarized light. Ice drag is estimated as 40–50% of total energy dissipation in a skeleton run. The experimental results are compared with visual inspections of skeleton tracks, and to similar behaviour in rocks during sliding on earthquake faults. The results presented may be useful to athletes and designers of winter sports equipment. This article is part of the themed issue ‘Microdynamics of ice’.

A perturbative approach to the backflow dynamics of nematic defects

2011 ◽  
Vol 23 (1) ◽  
pp. 181-200 ◽  
Author(s):  
PAOLO BISCARI ◽  
TIMOTHY J. SLUCKIN
Keyword(s):  
Liquid Crystal ◽  
Energy Dissipation ◽  
Velocity Field ◽  
Total Energy ◽  
Asymptotic Theory ◽  
Perturbative Expansion ◽  
Perturbative Approach ◽  
Director Dynamics ◽  
Charged Defects ◽  
Total Energy Dissipation

We present an asymptotic theory that includes in a perturbative expansion the coupling effects between the director dynamics and the velocity field in a nematic liquid crystal. Backflow effects are most significant in the presence of defect motion, since in this case the presence of a velocity field may strongly reduce the total energy dissipation and thus increase the defect velocity. As an example, we illustrate how backflow influences the speeds of opposite-charged defects.

scholarly journals An Investigation of Differences in Lower Extremity Biomechanics During Single-Leg Landing From Height Using Bionic Shoes and Normal Shoes

2021 ◽  
Vol 9 ◽  
Author(s):  
Datao Xu ◽  
Huiyu Zhou ◽  
Julien S. Baker ◽  
Bíró István ◽  
Yaodong Gu
Keyword(s):  
Energy Dissipation ◽  
Total Energy ◽  
Lower Limb ◽  
Sagittal Plane ◽  
Reaction Force ◽  
Frontal Plane ◽  
Flexion Angle ◽  
Initial Contact ◽  
Lower Limb Injury ◽  
Total Energy Dissipation

Bionic shoes utilizing an actual foot shape sole structure can alter lower limb’s biomechanics, which may help in the development of specific training or rehabilitation programs. The purpose of this study was to investigate the biomechanical differences in the lower limb during a single-leg landing task using bionic shoes (BS) and normal shoes (NS). Fifteen healthy male subjects participated in this study, sagittal, and frontal plane data were collected during the landing phase (drop landing from 35 cm platform). Our study showed that BS depicted a significantly greater minimum knee flexion angle at initial contact (p = 0.000), a significantly greater minimum (initial contact) hip flexion angle at initial contact (p = 0.009), a significantly smaller sagittal plane total energy dissipation (p = 0.028), a significantly smaller frontal plane total energy dissipation (p = 0.008), a significantly smaller lower limb total energy dissipation (p = 0.017) than NS during the landing phase. SPM analysis revealed that BS depicted a significantly smaller knee joint vertical reaction force during the 13.8–19.8% landing phase (p = 0.01), a significantly smaller anterior tibia shear force during the 14.2–17.5% landing phase (p = 0.024) than NS. BS appears to change lower limb kinematics at initial contact and then readjust the landing strategies for joint work and joint reaction force, thereby reducing the risk of lower limb skeletal muscle injury. BS have great potential for future development and application uses, which may help athletes to reduce lower limb injury risk.

An Offset Reduction Technique for Latch Type Sense Amplifier in High Performance and High Density SRAM

2012 ◽  
Vol 542-543 ◽  
pp. 769-774
Author(s):  
Qun Ling Yu ◽  
Na Bai ◽  
Yan Zhou ◽  
Rui Xing Li ◽  
Jun Ning Chen ◽  
...  
Keyword(s):  
High Performance ◽  
Circuit Simulation ◽  
Cmos Technology ◽  
Optimal Operation ◽  
Reduction Technique ◽  
Total Speed ◽  
Sense Amplifier ◽  
Simulation Results ◽  
A New Technique ◽  
Total Energy Dissipation

A new technique for reducing the offset of latch-type sense amplifier has been proposed and effect of enable signal voltage upon latch-type sense amplifier offset in SRAM has been investigated in this paper. Circuit simulation results on both StrongARM and Double-tail topologies show that the standard deviation of offset can be reduced by 31.23% (StrongARM SA) and 25.2% (Double-tail SA) , respectively, when the voltage of enable signal reaches 0.6V in TSMC 65nm CMOS technology. For a column of bit-cell (1024 bit-cell), the total speed is improved by 14.98% (StrongARAM SA) and 22.26% (Double-tail SA) at the optimal operation point separately, and the total energy dissipation is reduced by 30.45% and 29.47% with this scheme.

An Analysis on the Forming Load of AA 2024 Aluminium Alloy in Combined and Sequence Operation Process

2006 ◽  
Vol 519-521 ◽  
pp. 949-954 ◽  
Author(s):  
Beong Bok Hwang ◽  
J.H. Shim ◽  
Jung Min Seo ◽  
H.S. Koo ◽  
J.H. Ok ◽  
...  
Keyword(s):  
Finite Element ◽  
Load Capacity ◽  
Low Cost ◽  
Forming Load ◽  
Mechanical Press ◽  
Combined Operation ◽  
Aa 2024 ◽  
Load Characteristics ◽  
Simulation Results ◽  
Selection Of

This paper is concerned with the analysis of the forming load characteristics of a forward-backward can extrusion in both combined and sequence operation. A commercially available finite element program, which is coded in the rigid-plastic finite element method, has been employed to investigate the forming load characteristics. AA 2024 aluminum alloy is selected as a model material. The analysis in the present study is extended to the selection of press frame capacity for producing efficiently final product at low cost. The possible extrusion processes to shape a forward-backward can component with different outer diameters are categorized to estimate quantitatively the force requirement for forming forward-backward can part, forming energy, and maximum pressure exerted on the die-material interfaces, respectively. The categorized processes are composed of combined and/or some basic extrusion processes such as sequence operation. Based on the simulation results about forming load characteristics, the frame capacity of a mechanical press of crank-drive type suitable for a selected process could be determined along with securing the load capacity and with considering productivity. In addition, it is suggested that different load capacities be selected for different dimensions of a part such as wall thickness in forward direction and etc. It is concluded quantitatively from the simulation results that the combined operation is superior to sequence operation in terms of relatively low forming load and thus it leads to low cost for forming equipments. However, it is also known from the simulation results that the precise control of dimensional accuracy is not so easy in combined operation. The results in this paper could be a good reference for analysis of forming process for complex parts and selection of proper frame capacity of a mechanical press to achieve low production cost and thus high productivity.

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