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Energy Efficiency and Conservation Technologies
Published in Swapan Kumar Dutta, Jitendra Saxena, Binoy Krishna Choudhury, Energy Efficiency and Conservation in Metal Industries, 2023
Jitendra Saxena, Binoy Krishna Choudhury
First Law of Thermodynamics: “Energy and materials are always conserved.” Outcome includes equations of energy and mass balance, which are said to be the law of conservation of mass and the law of conservation of energy. The sum total of mass (and energy) remain constant in an isolated system and in the universe, as long as the nuclear reaction, represented by E = mC2, is not taking place. In a nuclear reaction, loss of mass (rest mass) times (velocity of light in free space squared) equals the amount of (thermal) energy released. Therefore, in the absence of a nuclear reaction, energy can be neither created nor destroyed, and only can change its form—say from potential energy to kinetic energy, or vice versa. Other forms of energy can be shown to be either one of these two. For example, current electricity, rotating shaft, moving particles, light, heat, etc., are examples of kinetic energy. On the other hand, static electricity, chemical energy, magnetic energy, energy due to position of a mass in a gravitation field, magnetism, etc., are examples of potential energy.
Energy
Published in William Bolton, Engineering Science, 2020
Consider an object of mass m being lifted from the floor through a vertical height h (Figure 7.11). If the object has a weight mg then the force that has to be applied to move the object is mg and the distance through which the point of application of the force is moved in the direction of the force is h. Thus the work done is mgh. This is the energy transferred to the body. Energy an object has by virtue of its position is called potential energy. Thus the object gains potential energy of:potentialenergy=mgh
Current, voltage and resistance
Published in Mike Tooley, Lloyd Dingle, Engineering Science, 2020
From your study of dynamic engineering systems you will recall that energy can exist in many forms including kinetic energy, potential energy, heat energy, light energy etc. Kinetic energy is concerned with the movement of a body whilst potential energy is the energy that a body possesses due to its position. Energy can be defined as ‘the ability to do work’ whilst power can be defined as ‘the rate at which work is done’.
Numerical and experimental evaluation of adhesion properties of asphalt-aggregate interfaces using molecular dynamics simulation and atomic force microscopy
Published in Road Materials and Pavement Design, 2021
Bingyan Cui, Xingyu Gu, Hao Wang, Dongliang Hu
In this study, the Condensed-Phase Optimized Molecular Potentials for Atomistic Simulation Studies (COMPASS) II force field was used to describe the interactions between different particles in the asphalt-aggregate system. Its application on the asphalt-aggregate system has been validated by previous studies (Dong et al., 2017; Xu & Wang, 2016b, 2017). The total energy of the system can be divided into potential energy and kinetic energy. The potential energy is the energy related to the relative position of molecules due to the interactions. It is equal to the summation of valence energy and non-bond energy, as shown in Equation (1) (Sun et al., 2016). where Ep is the potential energy of the system; Eval is the valence energy of the system, including bond stretching, angle bending, dihedral torsion, out-of-plane bending and cross coupling terms; Enb is the non-bonded energy composed of van der Waals energy and coulomb electrostatic energy in Equations (2) and (3) (Sun et al., 2016). where EvdW is the van der Waals energy of system; rij is the distance between atom i and atom j; ϵij and rij0 are the constant L-J parameters for ij atom pairs; Eele is the electrostatic energy of system; qi and qj are the charge of atom i and atom j, respectively.
Line position optimization method for mountain roads based on slope stability and earthwork balance
Published in Journal of the Chinese Institute of Engineers, 2023
Pengru Wei, Ziyang Zhang, Xianghai Meng
Tu et al. (2016) concluded energy calculation method. For a slope system in numerical calculation software such as FLAC 3D, once the ground stress is balanced in the numerical model, two types of energy emerge, as follows: Gravitational potential energy;Elastic strain energy, which is generated by the gravitational potential energy.
A review of hydro-pneumatic and flywheel energy storage for hydraulic systems
Published in International Journal of Fluid Power, 2018
Paul M. Cronk, James D. Van de Ven
The most common and technologically mature method of storing energy in hydraulic systems is the accumulator. This device converts hydraulic power into potential energy. This potential energy can be a compressed gas, a strained elastic material, a compressed metal spring or a lifted weight. Gas-charged accumulators are the most common, and include several architectures that differ in the method of separating the pressurised gas from the hydraulic fluid, using either a piston, diaphragm or bladder.