An Association Study of Energy and Substance Transformations in Ripening Process of Banana Damaged by Loading Force

The research on the damage banana quality with loaded mechanical energy has significance to its storage, but there are few researches at present. This paper investigated 3 indexes of the energy and substance transformation in the damage banana by loading, including the change of the respiration rate CO2, the maximum impact stress intensity of fruit re-enduring and the maximum mechanical energy etc. during the storage. The results showed that there existed a significant association between the energy conversion and quality characteristics for the damaged banana, and the energy transformation affected the individuals physiological and biochemical process. There presented a significant trend on the intensity of the loading mechanical energy against the quality characteristics on above 3 indexes during the storage, but the difference between the individual had little effects on it. Decreasing the energy and substance transformation in damage area are the important means of extending the physiology life of fruits, which is an urgent problem to be solved in their field of processing and storage at present.

The triboelectric nanogenerator (TENG) reflects a prospering field, that uses Maxwell's displacement current as the driving force to transform mechanical energy into electricity. Based on the law of energy conservation, many theoretical models of TENGs are proposed to provide a detailed insight into how energy flows and transformation in the energy harvesting system, while ignoring a hidden but extremely important point about TENG's momentum transfer and conservation. Here a series of analysis is presented for the momentum transfer and conservation in TENGs based on Maxwell equations and stress tensor. Using a time‐dependent 3D mathematical model, it is elaborated that how the time‐ and spatial‐dependent momentum current is influenced by the field and the dielectric materials, demonstrating that momentum is overall conserved for a TENG. In other words, the TENG device can not only convert mechanical energy into electricity, but it is also able to transfer momentum. Momentum transfer is another important characteristic of TENGs, and finally, the essential differences and similarities among the momentum transfer, energy transfer, and energy transformation in TENGs are systematically discussed. This study will certainly serve as a new starting point for exploring momentum transfer and conservation in the TENG momentum transfer system.

This study investigates the effect of rubber particles on biaxial shear responses of sand–rubber mixtures (SRMs) using a multibody mesh-free method, which enables the flexible and robust modelling of visco-elastic deformation of rubber particles. From the energy evolutions in SRMs with different rubber contents (RCs), including the incremental elastic strain energy, friction slipping dissipation and damping dissipation, it is found that the slipping dissipation is much more severe than damping dissipation for specimens with lower RC, but less significant for specimens with greater RC during shearing. In addition, the fraction of incremental strain energy increases with RC. Further investigations on the evolutions of force chain networks of SRMs indicate that the incorporation of rubber particles facilitates the stability of strong force chains by mitigating particle rotations in the strong force chains and relative sliding in the weak contacts. It is observed that the energy transformation in sheared SRMs has a strong correlation with their microstructural evolution.

Variable-displacement pumps or generators form the primary part of a complete hydraulic energy transformer, the secondary part of which is a hydraulic motor. Hydraulic transformers of fluid drives are becoming more and more useful for all kinds of modern production machinery, such as presses, machine tools, automotive engines, cranes, etc., because of certain advantages offered along the line of the modern power-transmission problems. The flow of chemical energy occurs in the form of a fuel and air compound, into an internal-combustion engine, where it will be transformed to thermal and partly mechanical energy. The mechanical energy flows further in periodic impulses to the crankshaft of the engine in the form of a mechanical direct-current energy, where through the flywheel of the shaft it will be somewhat smoothed out, so that in a mechanical-electrical energy transformer it will be transformed to direct-current or alternating-current energy. These currents finally reach the electromotor of the shop, which operates the drive shafts of mechanical or hydraulic energy transmission apparatus, transmission-belt shafts, gear transmissions of machine tools, electromotors of press pumps, etc.

This paper presents the first experimental evidence of pronounced electrification effects upon reversible cycle of forced water intrusion-extrusion in nanoporous hydrophobic materials. Recorded generation of electricity combined with high-pressure calorimetric measurements improves the energy balance of {nanoporous solid + nonwetting liquid} systems by compensating mechanical and thermal energy hysteresis in the cycle. Revealed phenomena provide a novel way of "mechanical to electrical" and/or "thermal to electrical" energy transformation with unprecedented efficiency and additionally open a perspective to increase the efficiency of numerous energy applications based on such systems taking advantage of electricity generation during operational cycle.

We analyze a category of problems that is of interest in many physical situations, including those encountered in introductory physics classes: systems with two well-delineated parts that exchange energy, eventually reaching a shared equilibrium with a loss of mechanical or electrical energy. Such systems can be constrained by a constant of the system (e.g., mass, charge, momentum, or angular momentum) that uniquely determines the mechanical or electrical energy of the equilibrium state, regardless of the dissipation mechanism. A representative example would be a perfectly inelastic collision between two objects in one dimension, for which momentum conservation requires that some of the initial kinetic energy is dissipated by conversion to thermal or other forms as the two objects reach a common final velocity. We discuss how this feature manifests in a suite of four well-known and disparate problems that all share a common mathematical formalism. These examples, in which the energy dissipated during the process can be difficult to solve directly from dissipation rates, can be approached by students in a first-year physics class by considering conservation laws and can therefore be useful for teaching about energy transformations and conserved quantities. We then illustrate how to extend this method by applying it to a final example.

Compilation of a thermodynamics based process signature for the formation of residual surface stresses in metal cutting

Renewable energy, stored in the oceans, is in the form of heat, kinetic energy, chemical energy, and biological energy. Similar to the other sources of renewable energy, the dynamics of the oceans is an ideal energy resource. The aim of our study is to present the design of a new integrated system for harvesting the wave energy. The integrated system consists of an air turbine and a water turbine with oscillating blades. The paper also discusses the strength of the tides and the efficiency of the sea and ocean waves' energy transformation in mechanical energy.

Explosion is an extremely quick process of physical or chemical energy release. In other words, it is the transformation of energy from one form into one or more other forms within a relatively short span of time and within a certain space, and this conversion process is accompanied by powerful mechanical effects. The explosion of the common explosive is the conversion of chemical energy into mechanical energy, while nuclear explosion is the conversion of nuclear reaction energy into mechanical energy. Explosive weapons that utilize common explosives are called conventional explosive weapons, while explosive weapons that use nuclear reaction energy are called nuclear weapons. In terms of conventional explosive weapons, based on method of effect and intended targets, one system of categorizing such explosive weapons include lethal and blast weapons, anti-armor and anti-structure weapons, thermobaric weapons, and simple explosive weapons.

The mechanical energy is to our disposition in the arbitrary quantities. It belongs to the most ecological energies. Also the transformation to the other forms of energy is an ecological one. In the paper the transformation of mechanical energy to the other forms as the acoustic, light, high energy photons as well as nuclear particles has been shown. The quantumphysical theory of the transformation of the mechanical energy to the electromagnetic one particularly to the light has been reported.

Releasing constrains of the chemical bonds in the glass require a transformation of the thermal energy into the mechanical energy. By equating the mechanical and thermal energies, an equation could be obtained to calculate the glass transition temperature T g . The obtained equation shows that the ratios of the chemical components, the length of the bonds, and the stretching force constant are the most effective parameters for determining the value of T g . The obtained equation is applied successfully to haloborate and halomolybdate glasses.

An energy ‘sources’ and ‘fractions’ approach to the mechanical energy expenditure problem—III. Mechanical energy expenditure reduction during one link motion

Experimental demonstrations and theoretical analyses of a new electromechanical energy conversion process which is made feasible only by the unique properties of superconductors are presented in this dissertation. This energy conversion process is characterized by a highly efficient direct energy transformation from microwave energy into mechanical energy or vice versa and can be achieved at high power level. It is an application of a well established physical principle known as the adiabatic theorem (Boltzmann-Ehrenfest theorem) and in this case time dependent superconducting boundaries provide the necessary interface between the microwave energy on one hand and the mechanical work on the other. The mechanism which brings about the conversion is another known phenomenon - the Doppler effect. The resonant frequency of a superconducting resonator undergoes continuous infinitesimal shifts when the resonator boundaries are adiabatically changed in time by an external mechanical mechanism. These small frequency shifts can accumulate coherently over an extended period of time to produce a macroscopic shift when the resonator remains resonantly excited throughout this process. In addition, the electromagnetic energy in s ide the resonator which is proportional to the oscillation frequency is al so accordingly changed so that a direct conversion between electromagnetic and mechanical energies takes place. The intrinsically high efficiency of this process is due to the electromechanical interactions involved in the conversion rather than a process of thermodynamic nature and therefore is not limited by the thermodynamic value. A highly reentrant superconducting resonator resonating in the range of 90 to 160 MHz was used for demonstrating this new conversion technique. The resonant frequency was mechanically modulated at a rate of two kilohertz. Experimental results showed that the time evolution of the electromagnetic energy inside this frequency modulated (FM) superconducting resonator indeed behaved as predicted and thus demonstrated the unique features of this process. A proposed usage of FM superconducting resonators as electromechanical energy conversion devices is given along with some practical design considerations. This device seems to be very promising in producing high power (~10W/cm^3) microwave energy at 10 - 30 GHz. Weakly coupled FM resonator system is also analytically studied for its potential applications. This system shows an interesting switching characteristic with which the spatial distribution of microwave energies can be manipulated by external means. It was found that if the modulation was properly applied, a high degree (>95%) of unidirectional energy transfer from one resonator to the other could be accomplished. Applications of this characteristic to fabricate high efficiency energy switching devices and high power microwave pulse generators are also found feasible with present superconducting technology.

E n e r g y f l o w i n d i s s i p a t i v e s t r u c t u r e s y s t e m A concept of energy flow is very useful for tracing transfer and transformation of energy. A variety of energy, such as electromagnetic energy, mechanical energy, heat energy and etc. have corresponding energy flow forms, provided they can be transferred. It is known from dissipative structural theory that energy flow moving in the system plays an important role in forming of the dissipative structure, for example, producing a certain self-organization process, resulting in failure of original symmetric structure and forming a certain specific spatial structure and time evolutional sequence. The solid earth is considered as a dissipative structural system, in which transforming process of energy is caused by following energy flows (Degroot and Mazur, 1981). (1) Energy flow density produced by mechanical work acting on the system:

The object of the present communication is to call attention to the remarkable consequences which follow from Carnot's proposition, established as it is on a new foundation, in the dynamical theory of heat; that there is an absolute waste of mechanical energy available to man, when heat is allowed to pass from one body to another at a lower temperature, by any means not fulfilling his criterion of a “perfect thermo-dynamic engine.” As it is most certain that Creative Power alone can either call into existence or annihilate mechanical energy, the “waste” referred to cannot be annihilation, but must be some transformation of energy. To explain the nature of this transformation, it is convenient, in the first place, to divide stores of mechanical energy into two classes—statical and dynamical.