Thermodynamics of Irreversible Processes

We propose a microphysical theory of the triboelectric effect by which mechanical rubbing separates charges across the interface between two surfaces. Surface electrons are treated as an open system, weakly coupled to two baths, corresponding to the bulk materials. We show that work can be extracted from the motion-induced population inversion of fermions, thus extending and generalizing Zel'dovich's theory of bosonic superradiance. We argue that this is consistent with the basic phenomenology of triboelectrification and triboluminescence as off-equilibrium processes.

In this paper, using the combination of the first and second laws of thermodynamics, the work bounds in thermodynamic cycles are investigated generally and, to show the application, the results are extracted for some physical systems. Also, a new concept on the available work limits is extracted. To provide information on the maximum or minimum amount of work to be done during a thermodynamic cycle, energy balance, as well as irreversibility, should be considered. Entropy production during a thermodynamic cycle as a limiting criterion for work to be done is expressed as Clausius inequality. Therefore an inequality extracted from the first and second laws of thermodynamic to obtain lower and upper bounds of available work. The obtained upper bound of the work to be done is in agreement with Carnot's rule. The lower bound is obtained at the maximum possible irreversibility during the respective cycle.

This paper presents an exergy and environmental assessment of a 1000 metric t/day ammonia production plant based on the steam methane reforming (SMR) process, including the syngas production, purification (CO 2 capture) and compression units, as well as the ammonia synthesis and purge gas treatment. An integrated heat recovery system produces power and steam at three pressure levels, besides exporting hot water, CO 2 and fuel gas, with no additional heat or power consumption being required. Two configurations for ammonia refrigeration process (À20 C) are compared in terms of power consumption. Exergy cost data for upstream processing stages of natural gas is used to calculate the extended exergy cost of the products of the plant, namely ammonia, CO 2 and fuel gas. Moreover, an appropriated methodology is employed to properly allocate the renewable and non-renewable exergy costs, as well as the CO 2 emissions of the reforming, shift and furnace stack among the products of the plant. By considering that the cost reduction of the combustion gases is a linear function of the exergy flow rate reduction in each component of the heat recovery system, an improved allocation of the CO 2 emission cost along the convection train is performed. A breakdown of the total exergy destruction rate of the plant (136.5 MW) shows that about 59% corresponds to the reforming process followed far behind by the ammonia synthesis and condensation (18.3%) and the gas purification units (13.2%). The overall exergy efficiency of the ammonia plant is calculated as 66.36%, which is enhanced by recovering the hydrogen-rich and fuel gases in the purge gas treatment process. The total and non-renewable exergy costs and CO 2 emission cost of the ammonia produced are calculated as 1.7950 kJ/kJ and 0.0881 kg CO2 /MJ, respectively. In addition, a rational exergy cost of 1.6370 kJ/kJ and CO 2 emission cost of 0.0821 kg CO2 /MJ are allocated to the CO 2 gas, which can be supplied as feedstock to an associated chemical plant (urea, methanol, polymers, etc.).

We propose a microphysical theory of the triboelectric effect by which mechanical rubbing separates charges across the interface between two materials. Surface electrons are treated as an open system coupled to two baths, corresponding to the bulks. Extending Zel'dovich's theory of bosonic superradiance, we show that motion-induced population inversion can generate an electromotive force. We argue that this is consistent with the basic phenomenology of triboelectrification and tri-boluminescence as irreversible processes, and we suggest how to carry out more precise experimental tests.

From thermodynamics point of view, in this era of aiming at energy conservation and sustainability, we need to develop more accurate ways to design thermal power, cooling and heat pump cycles. It has been the general practice in thermodynamic analysis of cycles to use the Carnot efficiency and Carnot coefficient of performance (COP) which are the highest upper bound to efficiency and COP of cycles. In the present report through the application of the 2nd law of thermodynamics for irreversible processes, which results in the general inequality relation for the entropy production, we have introduced new upper- and lower-bounds to the efficiency of thermal power cycles and COP of cooling and heat pump cycles. The resulting upper- and lower-bounds are closer to the actual efficiency and COP of cycles. That allows us a more precise design of cycles and the choice of cycles’ working fluids.

In the framework of thermodynamics of irreversible processes, patterns of macroscopic evolution of operating organized systems from various fields (engineering, biology, cosmology) are coupled to the increase of their entropy. An extension of Boltzmann's equation is proposed to characterize the entropy evolution. It is shown that such 'top-down' approach allows to merge empirical data in a single inclusive model. A method is proposed to quantitatively assess the minimum semantic information gained during the life of the systems. This allows to compare systems with different types of organization and lifespans. An example of calculation is given for the universe. The method also offers challenging view to 'bottom-up' approaches in progress.

It is the general practice in engineering to use the Carnot efficiency and Carnot coefficient of performance (COP) as the upper-bounds to efficiency and COP of cycles, respectively.  In the present paper through the application of the 2nd law of thermodynamics for irreversible process it is shown that:  i). The Carnot efficiency and COP are not necessarily close upper-bounds to the real efficiency and COP.  ii). The 2nd law of thermodynamics generally gives us efficiency and COP upper-bound relations, which are closer to the real efficiency and COP than the Carnot relations.  iii). The new efficiency and COP upper-bound relations are in rather simple algebraic forms which can be utilized for energy efficiency analysis of processes. It is also shown that we are now able to produce lower-bounds to efficiency and COP of processes through the use of the 2nd law of thermodynamics. The resulting upper- and lower-bounds to efficiency and COP allow us to analyze a process more precisely than the mere use of the Carnot efficiency and COP relations.

Off-shellness and inhomogeneities are in the non-equilibrium dynamics of the lambda phi4 model are studied using the closed timepath formalism reformulated as kinetic field theory. We take into account initial correlations up to the 4-point functions. The model is shown to exhibit a SO(1,1) symmetry broken by interactions and initial conditions. The divergence of the corresponding Noethercurrent is calculated and the Ward-Takahashi relations for the broken symmetry are given. They constitute a set of generalized integrated kinetic equations for the general n-point functions. We demonstrate that energy-momentum conservation follows from the transport equations. As an application we discuss inhomogeneities and general non-equilibrium conditions in the free field model. In our solution we identify the casimir-effect.

This Guide is one of a series produced for GBH Enterprises.

The calculation of chemical equilibria for a single notional reaction is rarely difficult. A typical example is given in GBHE-PEG-RXT-813. The solution of such cases is well understood; the mass action equation generates a polynomial relationship between conversion and equilibrium constant (or free energy) which can be solved (at worst iteratively) and the relevant root selected by inspection.

Extension of this approach to more than one reaction rapidly becomes untenable for hand calculation due to the highly non-linear nature of the resulting simultaneous equations. The solution of these multi-reaction equilibrium problems has been investigated since the early days of the Second World War when interest in rocket motor design became strategically important. Indeed, work for the V2 at the "Hermann Göring Air Force Research Institute" provided some of the earliest papers on the subject.

To this day, combustion/explosion problems remain the mainspring of research effort in this area and a number of commercially available computer programs have appeared in the public domain.

Exposure of polymethylmethacrylate (PMMA) during electron beam lithography (EBL) produces small polymer fragments that dissolve rapidly during the development process. The resist dissolution behavior varies greatly depending on the nature of the developer (solvent) and therefore influences the selection of the EBL parameters, such as dose (sensitivity). A molecular scale examination of the development process is necessary to elucidate the resist–developer interaction mechanisms. In this work, the authors investigate the interaction of short PMMA chains (containing up to 10 MMA units) with common developer components methyl isobutyl ketone (MIBK) and isopropyl alcohol (IPA). For this purpose, the authors conduct molecular dynamics simulations using the Accelrys Materials Studio package. The simulation results were used to characterize the mixtures in the spirit of the Flory–Huggins theory of polymers and also to extract the diffusivities. The authors found that the behavior of PMMA fragments differed considerably in MIBK as compared with IPA. PMMA fragments containing more than three monomers exhibit stronger attractive interaction with MIBK. For all fragment sizes simulated, the diffusivity of PMMA fragments is 60–160% higher in MIBK as well. Similarly, the authors observed differences in the gyration radii. The authors conclude that the kinetic factor seems to be more significant as compared to affinity factor when accounting for differences in exposure sensitivities due to developer selection.

Air-cooled Data Centers (DCs) require effective thermal management of the servers which can be accomplished by implementing new cooling architectures. Nearly 33% of overall energy consumption is attributed to the cooling infrastructure, which indicates the importance of the specific cooling configuration. Our objective is to compare four emerging and traditional DC cooling architectures, (a) in-row cooling, (b) rack-mountable cooling (RMC), (c) underfloor air delivery (UFAD), and (d) overhead air delivery. Since a first law-based energy analysis of a DC cooling architecture seldom considers irreversibility and component level inefficiency, an exergy-based analysis provides an alternate basis of assessment. We propose a methodology that combines computational fluid dynamics simulations with thermodynamic energy and exergy balances to determine the exergy loss in different components in DC. A dimensionless parameter is identified to characterize the exergy loss as a function of the Peclet number and the dimensionless dead state temperature ratio. The architecture containing RMC unit has the lowest exergy loss. The chiller loss constitutes up to 55% of the overall exergy loss. This analysis facilitates better decision making and design choices for air-cooled DCs based on minimizing thermodynamic irreversibility to lower energy waste.

Difference of hydrogen solid solution limits in zirconium alloys for hydride formation and dissolution (solubility hysteresis) has been estimated based on general physical assumptions, and sensitivity to model parameters was investigated. Five energy dissipation mechanisms during the phase transition responsible for the hysteresis value were identified. Comparison of experimental data and the estimation demonstrates satisfactory agreement under the model assumptions.

It is shown that in diffusionless coherent first-order phase transformations in stressed solids an energy-momentum tensor appears in the role of a chemical potential. A thermodynamic equilibrium condition is derived in terms of this tensor from balance relations and a dissipation inequality, and its use in formulating linear phenomenological relations for irreversible phase transformations in nonhydrostatic systems is pointed out.

We analyze the statistical complexity vs. entropy plane-representation of sampled chaotic attractors as a function of the sampling period {\tau}. It is shown that if the Bandt and Pompe procedure is used to assign a probability distribution function (PDF) to the pertinent time series, the statistical complexity measure (SCM) attains a definite maximum for a specific sampling period tM. If the usual histogram approach is used instead in order to assign the PDF to the time series, the SCM remains almost constant at any sampling period {\tau}. The significance of tM is further investigated by comparing it with typical times given in the literature for the two main reconstruction processes: the Takens' one in a delay-time embedding, and the exact Nyquist-Shannon reconstruction. It is shown that tM is compatible with those times recommended as adequate delay ones in Takens' reconstruction. The reported results correspond to three representative chaotic systems having correlation dimension 2 < D2 < 3. One recent experiment confirms the analysis presented here.

When a real fluid is expelled quickly from a tube, it forms a jet separated from the surrounding fluid by a thin, turbulent layer. On the other hand, when the same fluid is sucked into the tube, it comes in from all directions, forming a sink-like flow. We show that, even for the ideal flow described by the time-reversible Euler equation, an experimenter who only controls the pressure in a pump attached to the tube would see jets form in one direction exclusively. The asymmetry between outflow and inflow therefore does not depend on viscous dissipation, but rather on the experimenter's limited control of initial and boundary conditions. This illustrates, in a rather different context from the usual one of thermal physics, how irreversibility may arise in systems whose microscopic dynamics are fully reversible.

The absolute temperature T has a recognized physical meaning in equilibrium thermodynamics. The scale realized by the closely related Lagrange coefficient "beta" usually figures as an auxiliary scale. In this article, the scale spanned by "beta" is a proper intensive thermal quantity for equilibrium and, suitably generalized, for stationary non-equilibrium state description. The coefficient "beta" measures a relative deviation of a system state from the state of uniform distribution function.

The purpose of this paper is to present author's observation. The main topics in the paper are force, motion and time. All three (force, motion and time) are interconnected to space and energy. The commonly used term  "Spacetime‟ is an observation given to us by Einstein's general relativity. What spacetime really means is that time is related to gravity. We already know that[1] gravity is caused by mass(which is energy E= MC2) and[2] gravity is the curvature of space. Therefore, "time is not only related to space but also related to energy". This paper connects General relativity with thermodynamics, and it provides a solution to what causes force, motion and time.