scholarly journals Thermodynamic Proof That the Thermal Energy of a Uniform Fluid Never Converts into Its Own Mechanical Energy

ACS Omega ◽  
2020 ◽  
Vol 5 (33) ◽  
pp. 21076-21083
Author(s):  
Nobuo Yoshida
Keyword(s):  
Thermal Energy ◽  
Mechanical Energy ◽  
Uniform Fluid

scholarly journals Radiofrequency Ablation for Treatment of Symptomatic Uterine Fibroids

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Siân Jones ◽  
Peter O'Donovan ◽  
David Toub
Keyword(s):  
Radiofrequency Ablation ◽  
Thermal Energy ◽  
Thermal Ablation ◽  
Mechanical Energy ◽  
Symptomatic Relief ◽  
Uterine Fibroids ◽  
Ultrasound Waves ◽  
Associated Symptoms ◽  
Fibroid Volume

The use of thermal energy-based systems to treat uterine fibroids has resulted in a plethora of devices that are less invasive and potentially as effective in reducing symptoms as traditional options such as myomectomy. Most thermal ablation devices involve hyperthermia (heating of tissue), which entails the conversion of an external electromagnetic or ultrasound waves into intracellular mechanical energy, generating heat. What has emerged from two decades of peer-reviewed research is the concept that hyperthermic fibroid ablation, regardless of the thermal energy source, can create large areas of necrosis within fibroids resulting in reductions in fibroid volume, associated symptoms and the need for reintervention. When a greater percentage of a fibroid's volume is ablated, symptomatic relief is more pronounced, quality of life increases, and it is more likely that such improvements will be durable. We review radiofrequency ablation (RFA), one modality of hyperthermic fibroid ablation.

Thermo-mechanical energy harvesting and storage analysis in 0.6BZT-0.4BCT ceramics

2021 ◽  
Author(s):  
Satyanarayan Patel ◽  
Manish Kumar ◽  
Yashwant Kashyap
Keyword(s):  
Energy Storage ◽  
Energy Harvesting ◽  
Thermal Energy ◽  
Mechanical Energy ◽  
Energy Storage Density ◽  
Storage Density ◽  
Thermal Energy Harvesting ◽  
Polarization Electric Field ◽  
And Storage ◽  
Olsen Cycle

Present work shows waste energy (thermal/mechanical) harvesting and storage capacity in bulk lead-free ferroelectric 0.6Ba(Zr0.2Ti0.8)O3-0.4(Ba0.7Ca0.3)TiO3 (0.6BZT-0.4BCT) ceramics. The thermal energy harvesting is obtained by employing the Olsen cycle under different stress biasing, whereas mechanical energy harvesting calculated using the thermo-mechanical cycle at various temperature biasing. To estimate the energy harvesting polarization-electric field loops were measured as a function of stress and temperatures. The maximum thermal energy harvesting is obtained equal to 158 kJ/m3 when the Olsen cycle operated as 25-81 °C (at contact stress of 5 MPa) and 0.25-2 kV/mm. On the other hand, maximum mechanical energy harvesting is calculated as 158 kJ/m3 when the cycle operated as 5-160 MPa (at a constant temperature of 25 °C) and 0.25-2 kV/mm. It is found that the stress and temperature biasing are not beneficial for thermal and mechanical energy harvesting. Further, a hybrid cycle, where both stress and temperature are varied, is also studied to obtain enhanced energy harvesting. The improved energy conversion potential is found as 221 kJ/m3 when the cycle operated as 25-81 °C, 5-160 MPa and 0.25-2 kV/mm. The energy storage density varies from 43 to 66 kJ/m3 (increase in temperature: 25-81 °C) and 43 to 80 kJ/m3 (increase in stress: 5 to 160 MPa). Also, the pre-stress can be easily implemented on the materials, which improve energy storage density almost 100% by domain pining and ferroelastic switching. The results show that stress confinement can be an effective way to enhance energy storage.

Energy Analysis of Liquid Desiccant Based Evaporative Cooling System

2005 ◽  
Author(s):  
Faleh A. Al-Sulaiman ◽  
P. Gandhidasan
Keyword(s):  
Thermal Energy ◽  
Energy Analysis ◽  
Cooling System ◽  
Mechanical Energy ◽  
Evaporative Cooling ◽  
Zeolite Membrane ◽  
Solution Temperature ◽  
Regeneration System ◽  
Liquid Desiccant ◽  
Evaporative Cooling System

This paper presents preliminary findings of the energy analysis of a cooling system with multistage evaporative coolers using liquid desiccant dehumidifier between the stages. The proposed evaporative cooling system utilizes the air humidity for cooling in humid areas and requires no additional water supply. The major energy requirement associated with this cooling system is the energy for regenerating the weak liquid desiccant. In this paper two types of energy namely thermal energy as well as mechanical energy are considered for regeneration. For thermal energy, the heat input for regeneration is supplied from the conventional energy sources such as a simple line heater. Reverse osmosis (RO) process is considered for regeneration by mechanical energy and MFI zeolite membrane is proposed for separation of water from the weak desiccant solution. Energy analysis has been carried out for both methods of regeneration. The results show that the energy consumption is about 25% less for the mechanical regeneration system with 3 % recovery than the thermal energy regeneration system to increase the desiccant solution temperature of 22°C. The COP of the proposed cooling system is defined as the cooling effect by the mass rate of water evaporated in the system divided by the amount of energy supplied to the system, that is, the COP is independent of the energy source.

scholarly journals A human body as an energy source

2021 ◽  
pp. 60-65
Author(s):  
Yevgen Honcharov ◽  
Nataliya Kriukova ◽  
Vladislav Markov ◽  
Igor Polyakov
Keyword(s):  
Thermal Energy ◽  
Human Body ◽  
Power Plants ◽  
Experimental Testing ◽  
Mechanical Energy ◽  
Living Organism ◽  
Electrical Energy ◽  
The Body ◽  
Charge Carriers ◽  
The Brain

The article deals with the actual problems of using the energy released by the human body. The question arises how much energy can the human body generate? Is it possible to use this energy for domestic and industrial needs? In the 18th and 19th centuries, the first scientific works on this topic appeared. It turned out that the charge carriers in the proteins of a living organism are protons and electrons, which, together with the electron-hole conduction system, create a single conductivity inherent only in a living organism. The electrical activity of the brain is assessed by voltage pulses with an amplitude of 500 μV of various frequencies from 0.5 to 55 Hz. It is impossible to receive pulses with such a frequency and such an amplitude from only ionic-type charge carriers. Electrochemical current sources are inertial; therefore, this fact can be direct evidence of the presence of electronic movement of charge carriers in the brain and the nervous system as a whole. It is quite realistic to use the thermal energy of the human body. Currently, the central building of the Stockholm railway station has been turned into a kind of experimental testing ground. Every day about 250 thousand people pass through the station building, who emit up to 25 MW of thermal energy. Most of it in the form of heated air is collected in ventilation and through heat exchangers energy is transferred to heat water in the heating system of another building. According to rough estimates, the efficiency of such a system can save up to 25% of the energy spent on heating the building. Inside a person, electric currents of various frequencies are generated in 7 biological power plants: in the heart, in the brain and in the five sense organs. All the electricity that is generated inside the human body is absorbed by its own tissues. Not a single electron produced inside a living organism leaves the human body, and does not pass into the environment, but is absorbed by the skin. This is the reason for the closure of the human electrical system. The body itself absorbs all the electricity that it previously produced. The energy generated by the human body is divided into mechanical, thermal, and electrical. The thermal energy of the human body can be used most effectively. Mechanical energy can also be used, but with much less efficiency. The electrical energy of the human body at this stage in the development of science and technology is practically impossible to use. Its use is likely to become real in the very distant future

scholarly journals Affects of the Cold Water Pipe Depth in Ocean Thermal Energy Converter Plants with respect to Power Generation Efficiency

2015 ◽  
Vol 2 ◽  
pp. 50-66 ◽  
Author(s):  
Helia Danielle Giordani ◽  
Matheus Lages ◽  
Miguel Medina ◽  
Jade Tan-Holmes
Keyword(s):  
Power Generation ◽  
Surface Water ◽  
Thermal Energy ◽  
Power Efficiency ◽  
Cold Water ◽  
Mechanical Energy ◽  
Heat Engine ◽  
Water Pipe ◽  
Generation Efficiency ◽  
Ocean Thermal Energy

The Ocean provides an extensive renewable energy source. It is the exploitation of the thermal gradient between the warmed surface water and the deep cold water. A heat engine was developed to use the surface water as a heat source and the deep water as a cold source in order to convert thermal energy into mechanical energy and generate electricity. This process is called Ocean Thermal Energy Conversion (OTEC). This paper presents the three different types of OTEC power plants: closed-cycle, open-cycle and hybrid-cycle, showing real and conceptual examples of each. All three systems are analyzed in terms of gross power, net power, efficiency and size. Furthermore, the depth of the cold water pipe is discussed and related to the net power generation of the OTEC plant. The power generation efficiency of the plant increases as the gross power production increases. This is due to the depth of the cold water pipe and amount of power used by the cold water pipe pump.

scholarly journals Application of Stirling Engine Type Alpha Powered by the Recovery Energy on Vessels

2020 ◽  
Vol 27 (1) ◽  
pp. 96-106
Author(s):  
Jacek Kropiwnicki
Keyword(s):  
Thermal Energy ◽  
Mechanical Energy ◽  
Structural Features ◽  
Stirling Engine ◽  
Engine Simulation ◽  
Engine Room ◽  
Stirling Engines ◽  
Potential Applications ◽  
The Impact ◽  
Engine Type

AbstractThe Stirling engine is a device in which thermal energy is transformed into mechanical energy without any contact between the heat carrier and the working gas enclosed in the engine. The mentioned feature makes this type of engine very attractive for the use of the recovery energy taken from other heat devices. One of the potential applications of Stirling engines is the use of thermal energy generated in the ship’s engine room for producing electricity. The work presents the concept of the Stirling engine type alpha powered by the recovery energy. The model of Stirling engine developed in this work allows a quantitative assessment of the impact of the design features of the engine, primarily the heat exchange surfaces and the volume of control spaces, on the achieved efficiency and power of the engine. Using an iterative procedure, Stirling engine simulation tests were carried out taking into account the variable structural features of the system. The influence of the size of the heater and the cooler, as well as the effectiveness of the regenerator and the temperature of the heat source on the efficiency and power produced by the Stirling engine have been presented.

Reflections on the Motive Power of Heat II

2010 ◽  
Author(s):  
George J. Mahl
Keyword(s):  
Thermal Energy ◽  
Mechanical Energy ◽  
Second Law Of Thermodynamics ◽  
Electrical Energy ◽  
Rankine Cycle ◽  
Second Law ◽  
Carnot Cycle ◽  
Original Analysis ◽  
Underlying Basis ◽  
The Relationship

This paper explores and challenges the underlying basis of the Second Law of Thermodynamics. The second law of thermodynamics and its related equations define the relationship between thermal energy and its conversion into mechanical work. The second law of thermodynamics and its equations are based on theory developed by analysis of the Carnot cycle, then with a leap of faith, applies this theory and these equations to the Rankine cycle and to the general conversion of thermal energy into mechanical energy. This paper explores the original analysis, which forms the basis of the second law of thermodynamics, and offers new analysis which may form a new understanding of thermodynamics. If proven correct, this new understanding may unlock tremendous resources for the production of mechanical and electrical energy.

Modeling and Characterization of PCM-Based Thermal Energy Harvesting

2017 ◽  
Author(s):  
Guangyao Wang ◽  
Dong Ha ◽  
Yi Chao ◽  
Kevin G. Wang
Keyword(s):  
Thermal Energy ◽  
Thermodynamic Model ◽  
Phase Change Materials ◽  
Plate Theory ◽  
Mechanical Energy ◽  
Thermomechanical Model ◽  
Energy Harvesters ◽  
Mechanics Model ◽  
Tait Equation Of State

This paper investigates the feasibility of using phase change materials (PCMs) to harvest the environmental thermal energy, which is often associated with a relatively low temperature differential, less than 100°C. First, we develop a thermodynamic model for an idealized setting based on Tait equation of state, thereby deriving a theoretical upper limit of the thermal efficiency that can be achieved using PCMs. Next, we couple the thermodynamic model with a structural mechanics model based on Kirchhoff-Love plate theory, and predict the performance of specific PCM-based energy harvesters that convert the harvested energy into mechanical energy. To validate the thermomechanical model and demonstrate the feasibility of the underlying approach, we present the development and characterization of a prototype device. The measured specific energy and the prediction of the thermomechanical model are in close agreement.

Using Thermal Shock to Transform Thermal Energy Into Work

2020 ◽  
Vol 142 (8) ◽  
Author(s):  
Zhengis Tileubay
Keyword(s):  
Thermal Shock ◽  
Thermal Energy ◽  
Mechanical Energy ◽  
Traditional Methods ◽  
Operational Capability

Abstract This article discusses the use of thermal shock to transform thermal energy into work. A new concept in understanding the laws of conversion of thermal energy into mechanical energy is presented. The relevance of the research in this direction is substantiated. The potential thermodynamic effectiveness of this process is determined. It presents higher efficiency compared with the traditional methods of converting heat into work based on the expansion of the working material. This article describes the method and the algorithm of the experiment to determine the operational capability of thermal shock and shows the predicted results of the experiments. The possibility to construct a completely new thermal engine with an efficiency of close to 100% is also mentioned.

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