scholarly journals A Note on Effects of Generalized and Extended Uncertainty Principles on Jüttner Gas

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 213
Author(s):  
Hooman Moradpour ◽  
Sarah Aghababaei ◽  
Amir Hadi Ziaie
Keyword(s):  
Distribution Function ◽  
Partition Function ◽  
Energy Density ◽  
Thermal Energy ◽  
Boltzmann Distribution ◽  
High Energy ◽  
Uncertainty Principles ◽  
Relativistic Limit ◽  
Boltzmann Statistics ◽  
Extended Uncertainty

In recent years, the implications of the generalized (GUP) and extended (EUP) uncertainty principles on Maxwell–Boltzmann distribution have been widely investigated. However, at high energy regimes, the validity of Maxwell–Boltzmann statistics is under debate and instead, the Jüttner distribution is proposed as the distribution function in relativistic limit. Motivated by these considerations, in the present work, our aim is to study the effects of GUP and EUP on a system that obeys the Jüttner distribution. To achieve this goal, we address a method to get the distribution function by starting from the partition function and its relation with thermal energy which finally helps us in finding the corresponding energy density states.

scholarly journals On Boundedness of Entropy of Photon Gas in Noncommutative Spacetime

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Kazi Ashraful Alam ◽  
Mir Mehedi Faruk
Keyword(s):  
Black Holes ◽  
Distribution Function ◽  
Phase Space ◽  
Partition Function ◽  
Boltzmann Distribution ◽  
Einstein Distribution ◽  
Entropy Bound ◽  
Photon Gas ◽  
Noncommutative Spacetime ◽  
Bose Einstein

Entropy bound for the photon gas in a noncommutative (NC) spacetime where phase space is with compact spatial momentum space, previously studied by Nozari et al., has been reexamined with the correct distribution function. While Nozari et al. have employed Maxwell-Boltzmann distribution function to investigate thermodynamic properties of photon gas, we have employed the correct distribution function, that is, Bose-Einstein distribution function. No such entropy bound is observed if Bose-Einstein distribution is employed to solve the partition function. As a result, the reported analogy between thermodynamics of photon gas in such NC spacetime and Bekenstein-Hawking entropy of black holes should be disregarded.

Towards High Energy Density, High Conductivity Thermal Energy Storage Composites

2012 ◽  
Author(s):  
Patrick J. Shamberger ◽  
Daniel E. Forero
Keyword(s):  
Thermal Conductivity ◽  
Energy Storage ◽  
Energy Density ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
High Energy ◽  
High Energy Density ◽  
Lithium Nitrate ◽  
Nitrate Trihydrate ◽  
Graphitic Foam

Thermal energy storage (TES) materials absorb transient pulses of heat, allowing for rapid storage of low-quality thermal energy for later use, and effective temperature regulation as part of a thermal management system. This paper describes recent development of salt hydrate-based TES composites at the Air Force Research Laboratory. Salt hydrates are known to be susceptible to undercooling and chemical segregation, and their bulk thermal conductivities remain too low for rapid heat transfer. Here, we discuss recent progress towards solving these challenges in the composite system lithium nitrate trihydrate/graphitic foam. This system takes advantage of both the high volumetric thermal energy storage density of lithium nitrate trihydrate and the high thermal conductivity of graphitic foams. We demonstrate a new stable nucleation agent specific to lithium nitrate trihydrate which decreases undercooling by up to ∼70% relative to previously described nucleation agents. Furthermore, we demonstrate the compatibility of lithium nitrate trihydrate and graphitic foam with the addition of a commercial nonionic silicone polyether surfactant. Finally, we show that thermal conductivity across water-graphite interfaces is optimized by tuning the surfactant concentration. These advances demonstrate a promising route to synthesizing high energy density, high thermal conductivity TES composites.

scholarly journals Mg-Based Hydrogen Absorbing Materials for Thermal Energy Storage—A Review

2018 ◽  
Vol 8 (8) ◽  
pp. 1375 ◽  
Author(s):  
Bo Li ◽  
Jianding Li ◽  
Huaiyu Shao ◽  
Liqing He
Keyword(s):  
Energy Storage ◽  
Energy Density ◽  
Energy Loss ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Storage ◽  
High Energy ◽  
Low Energy ◽  
Potential Candidate ◽  
Chemical Heat

Utilization of renewable energy such as solar, wind, and geothermal power, appears to be the most promising solution for the development of sustainable energy systems without using fossil fuels. Energy storage, especially to store the energy from fluctuating power is quite vital for smoothing out energy demands with peak/off-peak hour fluctuations. Thermal energy is a potential candidate to serve as an energy reserve. However, currently the development of thermal energy storage (TES) by traditional physical means is restricted by the relatively low energy density, high temperature demand, and the great thermal energy loss during long-period storage. Chemical heat storage is one of the most promising alternatives for TES due to its high energy density, low energy loss, flexible temperature range, and excellent storage duration. A comprehensive review on the development of different types of Mg-based materials for chemical heat storage is presented here and the classic and state-of-the-art technologies are summarized. Some related chemical principles, as well as heat storage properties, are discussed in the context. Finally, some dominant factors of chemical heat storage materials are concluded and the perspective is proposed for the development of next-generation chemical heat storage technologies.

scholarly journals Constant-volume vapor-liquid equilibrium for thermal energy storage: Generalized analysis of pure fluids

2020 ◽  
Vol 197 ◽  
pp. 01001
Author(s):  
Abdullah Bamoshmoosh ◽  
Gianluca Valenti
Keyword(s):  
Energy Storage ◽  
Energy Density ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage Capacity ◽  
High Energy ◽  
Constant Volume ◽  
Temperature Range ◽  
Energy Storage Capacity ◽  
Vapor Liquid

Thermal energy storage is of great interest both for the industrial world and for the district heating and cooling sector. Available technologies present drawbacks that reduce the margin of application, such as low energy density, limited temperature range of work, and investment costs. Phase transition is one of the main phenomena that can be exploited for thermal energy storage because of its naturally high energy density. Constant-volume vapor-liquid transition shows higher flexibility and increased heat transfer properties with respect to available technologies. This work presents a description of the behavior of these types of systems. The analysis is carried out through a generalized approach using the Corresponding State Principle. Variation of internal energy as a function of temperature over a fixed range is calculated at constant volume at different values of specific volume. It is shown that, for lower specific volumes, larger temperature ranges of work can be achieved without occurring in the steep pressure increase typically given by the expansion of liquid. Maximum operating temperature range is increased by up to 20% of the critical temperature with minimal energy loss. In optimal subsets of these ranges of temperature, the energy storage capacity of vapor-liquid systems increases at lower volumes, with energy storage capacity increasing to up to 40% with a 50% increase of the reduced volume. This is especially valid for more complex fluids, which are more interesting for these applications because of their higher heat capacity.

Dynamic Characteristics of a Free Piston Compressor

2004 ◽  
Author(s):  
Eric J. Barth ◽  
Jose Riofrio
Keyword(s):  
Energy Density ◽  
Thermal Energy ◽  
Power Supply ◽  
Piston Compressor ◽  
High Energy ◽  
Small Scale ◽  
Total System ◽  
Electric Motors ◽  
Free Piston ◽  
Human Scale

The design and dynamic characterization of a free piston compressor is presented in this paper. The free piston compressor is a proposed device that utilizes combustion to compress air into a high-pressure supply tank. The device is configured such that the transduction from thermal energy to stored energy, in the form of compressed gas, is efficient relative to other small-scale portable power supply systems. This efficiency is achieved by matching the dynamic load of the compressor to the ideal adiabatic expansion of the hot gas combustion products. It is shown that a load that is dominantly inertial provides a nearly ideally matched load for achieving high thermodynamic efficiency in a heat engine. The device proposed exploits this fact by converting thermal energy first into kinetic energy of the free piston, and then compressing air during a separate compressor phase. The proposed technology is intended to provide a compact pneumatic power supply source appropriate for human-scale robots. The combined factors of a high-energy density fuel, the efficiency of the device, the compactness and low weight of the device, and the use of the device to drive lightweight linear pneumatic actuators (lightweight as compared with power comparable electric motors) is projected to provide at least an order of magnitude greater total system energy density (power supply and actuation) than state of the art power supply (batteries) and actuators (electric motors) appropriate for human-scale power output. A thermodynamic analysis reveals relationships between key design variables with regard to efficiency. A dynamic model of the proposed device is developed and simulation results are discussed. This model shows the potential of the proposed device.

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