Phase Transitions

The huge advance of high-pressure techniques came with the design of the diamond anvil cell (DAC) achieving multidisciplinary character. DAC makes possible to investigate the changes in the electronic properties induced by local or crystal modifications of the material under high pressures without changing the chemical composition (Fig. 1). Traditional spectroscopic techniques used in material characterization labs like optical absorption, luminescence, excitation, lifetimes or Raman can be systematically applied previous adaptation to work with microsamples. So, it is possible to establish different pressure effects on materials: energy level shifts, local structure modifications or structural phase transitions and their consequences on the electronic and vibrational properties; changes in color due to pressure (piezochromism), high spin to low spin transitions, excited-state crossovers, etc. The different sensitivity of excited states to crystal-field strength enables the energy tuning of the states responsible of the optical properties (usually d orbitals in transition metal ions and f orbitals in lanthanides) for inducing resonance between levels producing exotic effects like upconversion, i. e., convert low energy radiation into higher energy from the emitting ions. The aim of this contribution is to illustrate, with selected examples, the effect of pressure on insulators [1-4] and semiconductor materials [5], which have been explored in our group recently.

Remnant strain has been measured as a function of temperature in ͑Ba 0.8 Sr 0.2 ͒TiO 3 ͑BST͒ ceramic by mechanical poling in three point bending configuration. BST ceramic exhibits recoverable macroscopic strain with shape memory effect and three jumps in the temperature-dependent strain during thermal cycling under applied force. The jumps are associated with the three structural phase transitions of BST, as confirmed by the simultaneous measurements of dynamic modulus and internal friction. In addition, the orthorhombic phase of BST exhibits a significantly higher strain comparing to that in the tetragonal and rhombohedral phases. X-ray diffraction confirms that the macroscopic strain is due to ferroelastic domain switching and particularly the dominant contribution to the higher macroscopic strain at orthorhombic phase is the higher probability of non-180°domain switching rather than the variation of domain switching strain at different phases.

History shows that up to 1870’s, the thermodynamic cycles, particularly Carnot’s cycle, were the most important heuristic instruments as much to formulate the general laws of physics as well to deduce the experimental laws. From this moment on, this instrument falls into disuse with surprising rapidity. At the end of this decade emerges a new thermodynamic formulation, proposed by Gibbs, the thermodynamics of the potentials. This sudden transition from thermodynamic of cycles to potentials was triggered by the difficult to approach the emergence of the phase transition phenomena with the diagrammatic method. The main objective of the article is, then, to analyze the consequences of the substitution, by Gibbs, of the diagrammatic by the geometric method, particularly, its heuristic potential related to the proposal of the formulation of the thermodynamic of potentials.

Effect of the synthesis conditions of Pechini technique on crystallinity and purity of Na 3 Ce(PO 4) 2 compound was investigated. Nano-sized cerium-sodium phosphate obtained when EDTA was used as an additional chelating agent for Ln 3+. The total enthalpy change of Na 3 Ce(PO 4) 2 phase transition was determined as 14.2 ±0.7 kJ mol-1 for sample synthesized by conventional solid-solid reaction. The phase transition process was confirmed to occur at 1060°C or in temperature range 920-1060°C depending on thermal treatment of powders.

Polyethers based on bis(2-chloroethyl) ether and various bisphenols were obtained using a phase transfer catalysis technique in a liquid /liquid system. 4, bisphenol A, sulfide were used. Only the polymers with azobenzene and biphenyl units exhibited mesophases, since the others have semi-crystalline or amorphous structures. The polymers were characterized by 1 H NMR, DSC and optical microscopy in polarized light. The molecular weights of the samples were low, situated in the oligomeric domain. The various transfer rates of the bisphenols from the aqueous to the organic phase, in some cases, led to very different copolymerization ratios as compared to the feed ratios. The LC polymers exhibited monotropic mesophases, probably for conformational reasons. A comparison between similar polyether structures containing the diethyletheric spacer and an oxetanic one was effectuated. ZUSAMMENFASSUNG: Polyether aus Bis(2-chlorethyl)ether und verschiedenen Diphenolen wurden durch Phasentransferkatalyse in einem zweiphasigen flüssigen System hergestellt. Als Diphenol-Verbindungen wurden 4,49-Dihydroxyazobenzol, 4,49-Dihydroxybiphenyl, Bisphenol A, 2,7-Dihydroxynaphthalin und 4,49-Dihydroxydiphenylsulfid eingesetzt. Lediglich die Polymeren mit Azobenzol-und Diphenyleinheiten bildeten Mesophasen, wohingegen die anderen Produkte semikristalline oder amorphe Strukturen ausbildeten. Die Polymeren wurden durch 1 H NMR, DSC und Polarisationsmikroskopie charakterisiert. Die Proben besaßen niedrige Molekulargewichte im Bereich von Oligomeren. Die unterschiedlichen Transfergeschwindigeiten der Diphenole von der wäßrigen in die organische Phase führten in einigen Fällen zu vom Ausgangsmonomerverhältnis sehr verschiedenen Copolymerzusammensetzungen. Die flüssigkristallinen Polymeren bildeten, vermutlich aufgrund der Molekülkonformation, monotrope Mesophasen. Die Ergebnisse wurden mit denen von Polyethern ähnlicher Struktur mit Diethylether-und Oxetan-Spacern verglichen.

This paper is concerned with the topological modifications induced by heating in microporous materials and with the rules obeyed by them. Two main characteristics are always present in these reconstructive processes: (1) they occur owing to the breaking of T-O-T bridges and the migration of the tetrahedral cations to new sites, which have three vertices as before, whereas the fourth vertex can be shared or unshared by another tetrahedron (''face sharing tetrahedra'' process) (2) the T-O-T breaking occurs in the smallest ring in the structure (4-or 5-ring). Many factors can influence this process. Besides the topology, the chemical composition of the framework and extraframework, the synthesis conditions, also the heating modalities, either near or far from thermodynamic equilibrium conditions, can not only favour or prevent modification but also induce topologically different phases.

The formation of solid solutions of the type [Ba(HOC2H4OH)4][Ti1−x Gex (OC2H4O)3] as Ba(Ti1−x /Gex )O3 precursors and the phase evolution during thermal decomposition of [Ba(HOC2H4OH)4][Ti0.9Ge0.1(OC2H4O)3] (1) are described herein. The 1,2-ethanediolato complex 1 decomposes above 589 °C to a mixture of BaTiO3 and BaGeO3. A heating rate controlled calcination procedure, up to 730 °C, leads to a nm-sized Ba(Ti0.9/Ge0.1)O3 powder (1a) with a specific surface area of S = 16.9 m2/g, whereas a constant heating rate calcination at 1,000 °C for 2 h yields a powder (1b) of S = 3.0 m2/g. The shrinkage and sintering behaviour of the resulting Ba(Ti0.9/Ge0.1)O3 powder compacts in comparison with nm-sized BaTiO3 powder compacts (2a) has been investigated. A two-step sintering procedure of nm-sized Ba(Ti0.9/Ge0.1)O3 compacts (1a) leads, below 900 °C, to ceramic bodies with a relative density of ≥90%. Furthermore, the cubic ⇆ tetragonal phase transition temperature has been detected by dilatometry, and the temperature dependence of the dielectric constant (relative permittivity) has also been measured.

A simple monatomic system in two dimensions with a double-well interaction potential is investigated in a wide range of temperature by molecular dynamics simulation. The system is melted and equilibrated well above the melting temperature, and then it is quenched to a temperature 88% below the melting temperature Tm at several cooling rates to produce an amorphous state. Various thermodynamic quantities are measured as a function of temperature while the system is heated at a constant rate. The glass transiton is observed by a sudden increase of the energy and Tg is shown to be an increasing function of the cooling rate in the preparation process of the amorphous state. In a relatively-high temperature region, the system gradually transforms into crystals, and the time-temperature-transformation(TTT) curve shows a typical nose shape. It is found that the transformation time to a crystalline state is the shortest at a temperature 14 ∼ 15% below the melting temperature Tm and that at sufficiently low temperatures the transformation time is much longer than the available CPU time. This indicates that a long-lived glassy state is realized.

Ni-rich TiNi shape memory alloys were subjected to the effect of equal channel angular extrusion (ECAE) processes at 773 K by Bc path. The effects of ECAE processes on microstructures evolution and phase transformation behaviors were investigated. The initial 60-80 m equiaxed coarse grains of samples were elongated along the shearing force direction of ECAE and refined to 300-400 nm after eight passes ECAE. The R phase transformation of Ni-rich TiNi shape memory alloys was stimulated by ECAE processes within a larger temperature range. The martensite transformation peak temperature (Mp) dropped in previous 1-3 ECAE treatments, but the dropped Mp increased gradually with the increase of ECAE processes. Ti 3 Ni 4 phase was observed in the regions with high density of dislocations after ECAE treatment. Reasons for microstructures evolution and phase transformation changes were also discussed.

Microgels consisting of poly-N,N-diethylacrylamide (PDEAAM) and copolymer microgels consisting of N,N-diethylacrylamide-co-N-isopropylacrylamide (PDEAAM-co-PNIPAM) have been synthesized via free radical polymerizations. The volume phase transition of the microgels in aqueous solution was investigated by means of dynamic light scattering. All samples revealed a volume phase transition upon heating and the size change was fully reversible. An unusual dependence of transition temperature on the composition of the copolymer microgels was observed and samples were obtained with a transition temperature that was lower than that of both corresponding homopolymer particles. This synergistic behavior could be caused by strong hydrogen bonding between the mono-and the disubstituted acrylamide repeating units at nearly equimolar composition of the microgel.

The study of the thermodynamical stability of Fe 80 Ni 20 nanoparticles in the framework of embedded-atom method and moleculardynamics simulations shows evidence of large surface contributions to the free energy for particles with diameters up to 15 nm or more. The change of the free energy compared to its bulk value leads to a reduction of the martensitic equilibrium temperature, M 0 , and can suppress martensitic transformations in small particles. In addition the formation of martensite can be suppressed due to the lack of pre-existing nucleation sites necessary to overcome the energy barrier along the transformation path from austenite to martensite.

A thermochemical and thermophysical study has been carried out for crystalline barbital [5,5 0-diethylbarbituric acid]. The thermochemical study was made by static bomb combustion calorimetry, from which the standard (p ¼ 0:1 MPa) molar enthalpy of formation of the crystalline barbital, at T = 298.15 K, was derived as À(753.0 ± 1.8) kJ Á mol À1. The thermophysical study was made by differential scanning calorimetry over the temperature interval (265 to 470) K. A solid-solid phase transition was found at T = 413.3 K. The vapour pressures of the crystalline barbital were measured at several temperatures between T = (355 and 377) K, by the Knudsen mass-loss effusion technique, from which the standard molar enthalpy of sublimation, at T = 298.15 K was derived as (117.3 ± 0.6) kJ Á mol À1. The combination of the experimental results yielded the standard molar enthalpy of formation of barbital in the gaseous phase, at T = 298.15 K, as À(635.8 ± 1.9) kJ Á mol À1. This value is compared and discussed with our theoretical calculations by several methods (Gaussian-n theories G2 and G3, complete basis set CBS-QB3, density functional B3P86 and B3LYP) by means of atomization and isodesmic reaction schemes.

Electronic structure and refractive indices of SbSI crystal in paraelectric and ferroelectric phases were investigated by full-potential linearized augmented plane wave method with density functional theory. The temperature dependence of refractive indices along a-, b-, and c -axes and birefringence Δn = nc  − na as a function of photon energy were calculated near the phase transitions. The theoretical results were compared with experimental measurements of birefringence. Comparison between calculated increment of the birefringence δ(Δn 0 = nc  − na ) and experimental spontaneous polarization indicates the existence of the second-order phase transition at Tc 2 ≈ 240 K and confirms its relation to the P s.

The present study deals with preparation and swelling properties of micrometer-sized poly(N-isopropylacrylamide) (PNIPAM) hydrogel particles. Aqueous precipitation polymerization of NIPAM with N,N 0 -methylenebisacrylamide (MBAAm) was performed with varying electrolyte concentrations in the polymerization media. Sodium chloride was used as an electrolyte. According to the particle size analysis by transmission electron microscope, the particle size increased in the range of 0.55 to 1.60 mm with an increase in the electrolyte concentration up to 1.6 wt %. The concentration is based on the NIPAM monomer weight. Dynamic light scattering data showed that swelling ratio of PNIPAM hydrogel particles in water varied from 10 to 40 as the electrolyte concentration at particle preparation increased from 0 to 1.6 wt %. Time-course analysis of particle size showed that an increase in particle size would be caused by aggregation of smaller particles. In conclusion, micrometer-sized PNIPAM particles with high swelling capacity can be obtained by the addition of an electrolyte in polymerization media.

The opticaf absorption edge of CuInTer. CuGaS, and CuGaSe, single crystafs was measured as a function of hydrostatic pressure up to 2OCPa. In all cases the energy gap increases with pressure. From the data the pressure dependence of the energy gap (dE ,/dP) was determined as 22 meV GPa-l for CuInTel, 40meVGPa-'

Aims. We present positions and velocities for 796 planetary nebulae (PNe) in the Fornax Brightest Cluster Galaxy NGC 1316 (Fornax A). The planetary nebulae and existing kinematics are used to explore the rotation of this merger remnant and constrain dynamical models. Methods. Using FORS2 on the VLT, the PN velocities were measured using a counter-dispersed slitless-spectroscopy technique that produced the largest-to-date sample outside of the Local Group. Spherical, non-rotating, constant-anisotropy Jeans models were constrained by observations of the planetary nebulae and existing integrated light spectra. Results. The two-dimensional velocity field indicates dynamically-important rotation that rises in the outer parts, possibly due to the outward transfer of angular momentum during the merger. The modeling indicates a high dark matter content, particularly in the outer parts, that is consistent with previous estimates from dynamical models, lensing and stellar population models. Conclusions. The exceptionally large sample of PN velocities makes it possible to explore the kinematics of NGC 1316 in detail. Comparing the results to other early-type galaxies like NGC 1399 and NGC 4594 (M104, Sombrero), NGC 1316 represents a transition phase from a major-merger event to a bulge-dominated galaxy like NGC 4594.

The goal of this work is to compile the basic components for the construction of an electromagnetic field theory of consciousness that meets the standards of a fundamental theory. An essential cornerstone of the conceptual framework is the vacuum state of quantum electrodynamics which, contrary to the classical notion of the vacuum, can be viewed as a vibrant ocean of energy, termed zero-point field (ZPF). Being the fundamental substrate mediating the electromagnetic force, the ubiquitous ZPF constitutes the ultimate bedrock of all electromagnetic phenomena. In particular, resonant interaction with the ZPF is critical for understanding rapidly forming, long-range coherent activity patterns that are characteristic of brain dynamics. Assuming that the entire phenomenal color palette is rooted in the vibrational spectrum of the ZPF and that each normal mode of the ZPF is associated with an elementary shade of consciousness, it stands to reason that conscious states are caused by the coupling of the brain to a particular set of normal modes selectively filtered from the full frequency spectrum of the ZPF. From this perspective, the brain is postulated to function as a resonant oscillator that couples to a specific range of ZPF modes, using these modes as a keyboard for the composition of an enormous variety of phenomenal states. Theoretical considerations suggest that the brain-ZPF interface is controlled by altering the concentrations of neurotransmitters, placing the detailed study of the neurotransmitter-ZPF interaction at the center of future research activities.

Modeling of wax precipitation from hydrocarbon mixtures requires extended compositional data for the heavy fractions; as a result, the number of components in the mixture is usually large and phase equilibrium calculations are computationally expensive and may be prohibitive. A lumping procedure which reduces the dimensionality of phase equilibrium calculations without affecting the location of solid phase transitions is used. By lumping into pseudocomponents, some information on mixture behavior is lost; this information is recovered by a delumping (inverse lumping) procedure. Delumping acts as an interface between simulation tools and results involving different fluid representation levels. The key in the delumping procedure is to relate equilibrium constants of the detailed fluid to some quantities evaluated from lumped fluid flash results. A general form of a two-parameter cubic equations of state is used for vapor and liquid phases, and heavy components are assumed to precipitate in a single solid solution. The proposed lumping/delumping procedures are successfully tested for two synthetic mixtures and a typical reservoir fluid (gas-condensate). Very good agreement is obtained between phase distributions and component mole fractions of detailed and delumped systems. This is the first time that a delumping procedure is proposed for multiphase systems with solid phase precipitation.

Les interactions entre molécules des diverses phases impliquées dans les phénomènes de mouillage engendrent des interactions entre interfaces, qui influencent de façon profonde l'existence et la nature des transitions de mouillage. Cet ouvrage contribue à la compréhension de ce lien complexe entre interactions et transitions de mouillage, à partir de l'étude expérimentale du mouillage des alcanes sur l'eau et de considérations théoriques.
La thèse dont est issu cet ouvrage a été récompensée par le prix Ilya Prigogine 2001 de la meilleure thèse en thermodynamique.
Les toutes premières pages de l'ouvrage sont téléchargeables ici.

Solidi®cation (supercooled nematic-to-solid or supercooled smectic-A-to-solid), melting (solid-to-nematic or solid-tosmectic-A), smectic-A-to-nematic, and clearing (nematic-to-isotropic or smectic-A-to-isotropic) transition temperatures W s , W m , W AN , and W c , respectively, and enthalpies DH s , DH m , DH AN , and DH c , respectively, have been determined by differential scanning calorimetry (DSC) for members of the p-(n-alkyl)-p H -cyanobiphenyl (RCB) and the p-(n-alkoxy)-p H -cyanobiphenyl (ROCB) homologous series of liquid crystals, where`R' is the number of carbon atoms in the n-alkyl or n-alkyloxy tails. The study shows that the transition of the less ordered nematic phase to the more ordered smectic-A phase, in liquid crystals that exhibit both phases (those with R8 or 9), involves a transient phase of intermediate order. Broad or overlapping solidi®cation exotherms indicate that two mesogenic aggregations supercool simultaneously. Finally, there is evidence for a transition between two solid forms that occurs at temperatures preceding W m or concurrent with it depending on`R' and the heating rate. This refutes an earlier view that during melting the solid form with the higher melting point solidi®es. #

The structural phase transitions of the calcium titanate perovskite CaTiO 3 were investigated by the Rietveld analysis of hightemperature neutron and X-ray powder diffraction data in the temperature range of 296-1720 K. The present work demonstrates that the compound exhibits two reversible phase transitions of orthorhombic Pbnm-tetragonal I4/mcm and of I4/mcm-cubic Pm3m at 1498725 K and 1634713 K, respectively. No evidence of Cmcm phase is observed between the Pbnm and I4/mcm structures. The lattice parameters discontinuously change at the Pbnm-I4/mcm transition point, while a continuous change is observed for the I4=mcm2Pm3m transformation. These results indicate that the Pbnm-I4/mcm transition is of first order and that the I4=mcm2Pm3m transformation is of either second or higher order.

We predict that large-scale artificial intelligence systems and cognitive models will undergo sudden phase transitions from disjointed parts into coherent structures as their topological connectivity increases beyond a critical value. These situations, ranging from production systems to semantic net computations, are characterized by event horizons in space-time that determine the range of causal connections between processes. At transition, these event horizons undergo explosive changes in size. This phenomenon, analogous to phase transitions in nature, provides a new paradigm with which to analyze the behavior of large-scale computation and determine its generic features.

We clarify several subtle points in the CPN-1 model in 2 + 1 dimensions. It is shown that as a consequence of local gauge invariance the nA particles, belonging to fundamental representation of SU(N) do not appear in the spectrum (in any number of dimensions) regardless of the nature of the interaction between them. In 2 + 1 dimensions we analyse the phase structure of the theory from the point of view of realization of the relevant symmetries: SU(N)/ZN ⊗ UΦ(1) ⊗ UE(1). The symmetries UΦ(1) and UE(1) are gauge invariant analogs of the magnetic flux and electric charge symmetries in scalar QED. The charge of UE(1) is not related to the global part of the local U(1) transformations (which counts the difference between the number of n and the number of n∗ excitations). At the phase transition point the flavour SU(N) ZN is broken down to U(N−1) while the mode of implementation of the UΦ(1) is changed from Kosterlitz-Thouless to Wigner-Weyl. We provide a gauge invariant order parameter for the flavour symmetry breaking and identify the massless “photon” with the Kosterlitz-Thouless zero mode of UΦ(1).

We study self-organization of collective motion as a thermodynamic phenomenon in the context of the first law of thermodynamics. It is expected that the coherent ordered motion typically self-organises in the presence of changes in the (generalized) internal energy and of (generalized) work done on, or extracted from, the system. We aim to explicitly quantify changes in these two quantities in a system of simulated self-propelled particles and contrast them with changes in the system's configuration entropy. In doing so, we adapt a thermodynamic formulation of the curvatures of the internal energy and the work, with respect to two parameters that control the particles' alignment. This allows us to systematically investigate the behavior of the system by varying the two control parameters to drive the system across a kinetic phase transition. Our results identify critical regimes and show that during the phase transition, where the configuration entropy of the system decreases, the rates of change of the work and of the internal energy also decrease, while their curvatures diverge. Importantly, the reduction of entropy achieved through expenditure of work is shown to peak at criticality. We relate this both to a thermodynamic efficiency and the significance of the increased order with respect to a computational path. Additionally, this study provides an information-geometric interpretation of the curvature of the internal energy as the difference between two curvatures: the curvature of the free entropy, captured by the Fisher information, and the curvature of the configuration entropy.

An enthalpy formulation based fixed grid methodology is developed for the numerical solution of convection-diffusion controlled mushy region phase-change problems. The basic feature of the proposed method lies in the representation of the latent heat of evolution, and of the flow in the solid-liquid mushy zone, by suitably chosen sources. There is complete freedom within the me~odoIo~ for the definition of such sources so that a variety of phase-change situations can be modelled. A test problem of freezing in a thermal cavity under natural convection is used to demonstrate an application of the method.

The heat capacities at constant pressure of urea, N-methylurea, IV-ethylurea, N-(n)propylurea and N-(n)butylurea were measured by differential scanning calorimetry over the range 20& 360 K, in gas-flow conditions. A He + Ne mixture and N, only were selected as the purge gases below and above room temperature, respectively. Benzoic acid was used as the reference material and the accuracy of the measurements was estimated to be within 2% across the temperature range. The heat capacities at 298.15 K were obtained by interpolating the smoothed fitting equations. No anomalies were detected for urea or N-methylurea.

"Patterns in War Dynamics. WARning 2020". In this study, complexity and network science are applied to the dynamics and development of the (International) System. This study shows that the System periodically becomes critical and produces "systemic wars". The typical dynamics that are revealed in this study are a consequence of laws of physics that apply also to the System. Systemic wars are instrumental in rebalancing the System, and in periodically producing "upgraded" international orders that allow for further growth and development. The patterns that can be observed in the war dynamics of the System, make it possible to predict these dynamics and the System's direction of development.
Data-analysis shows that the System will again become critical around 2020 (+/- two years).
This study shows that intensifying war dynamics pose an existential threat to human kind: Systemic wars will cause increasing damage and suffering and will put our climate system at (additional) risk: Fundamental change is a prerequisite for our survival.
This study was initially published in 2016. The publication "On the Thermodynamics of War and Social Evolution" (2019) provides a scientific explanation for the war dynamics that can be observed.

William Shakespeare has developed the plot of his play Macbeth through the effective use of transitions<br> to the major characters. Among them, the character that is most prone to regular transitions in life is the<br> central character of Macbeth. This research paper explores the trajectory of transitions through which<br> Shakespeare develops the plot of his play through the character of Macbeth concerning his changing<br> situations and positions. While analysing the play with the help of Schlossberg's Transition theory,<br> specifically through the concept of 4S's, the perspicacity of Macbeth's trajectory of different transitions in<br> the pattern of one after the other is visible throughout the play. With the help of textual and<br> interpretative analysis of the play, the situation, psychological aspects, support and strategies to cope<br> with the transition in Macbeth are explored in the research. Through the pers...

This is an extension of the project I did where I computationally realised a 3D cubic lattice based on Ising model. In this project the focus is not just looking at the structure of various properties of the lattice at and around its critical temperature, but actually determining the critical temperature itself.

The application of the Arrhenius equation for the prediction of oxidative reaction rate in frozen foods is often precluded because of deviations from linearity. The latter are mainly caused by the occurrence of phase transitions of crystallizing components (that is, water, lipids, sugar). The aim of the present research was to study the temperature dependence of the lipid oxidation rate as affected by its physical state. To this purpose, the physical state and the oxidation rate of sunflower oil was evaluated from -30°C to 60°C. In this temperature range, sunflower oil presents different solid-liquid ratios because of the crystallization phenomena. A mathematical model accounting for both temperature and physical state was proposed to describe the kinetics of oxidation in the entire temperature range considered.

The study On the Thermodynamics of War and Social Evolution, shows that patterns can be identified in the war dynamics of the System, and that a relationship exists between these war dynamics and social evolution. The research suggests that Prigogine’s idea about non-equilibrium systems being able to attain highly ordered states in response to an increase of energy flux, can also be successfully applied to the social sciences. These new insights could have profound implications for our understanding of war (dynamics), and for our ability to better control and prevent war, in the future.I argue that the System can be considered a non-equilibrium system, and that the (relationship between) war dynamics - and the patterns they produce - and social evolution, can be explained from a (non-equilibrium) thermodynamic perspective: Interactions between components of the System (individual humans, communities, societies, states, etc.) are irreversible, and result in the production of entropy - tensions - in the System.
These tensions (entropy) serve as a source of order and are regulated by means of a dissipative structure that also puts kinetic activity (war) to use, to ensure the most efficient path to thermodynamic equilibrium of the System.

Conformal field theories arise near a phase transition when there are no scale involved. One usually talks about thermal phase transitions but a lot of the recent interest in condensed matter physics has been around quantum phase transitions which are phase transitions that happen as the coupling parameter is varied. In this case it turns out that the phase transition as well as the new phase arising from it, the quantum critical phase can be described in terms of the modifications of a conformal field theory.

We discuss canonical transformations in Quantum Field Theory in the framework of the functional-integral approach. In contrast with ordinary Quantum Mechanics, canonical transformations in Quantum Field Theory are mathematically more subtle due to the existence of unitarily inequivalent representations of canonical commutation relations. When one works with functional integrals, it is not immediately clear how this algebraic feature manifests itself in the formalism. Here we attack this issue by considering the canonical transformations in the context of coherent-state functional integrals. Specifically, in the case of linear canonical transformations, we derive the general functional-integral representations for both transition amplitude and partition function phrased in terms of new canonical variables. By means of this, we show how in the infinite-volume limit the canonical transformations induce a transition from one representation of canonical commutation relations to another one and under what conditions the representations are unitarily inequivalent. We also consider the partition function and derive the energy gap between statistical systems described in two different representations which, among others, allows to establish a connection with continuous phase transitions. We illustrate the inner workings of the outlined mechanism by discussing two prototypical systems: the van Hove model and the Bogoliubov model of weakly interacting Bose gas.

We study a model of cell segregation in a population composed of two cell types. Starting from a model initially proposed in [3], we aim to understand the impact of a cell division process on the system’s segregation abilities. The original model describes a population of spherical cells interacting with their close neighbors by means of a repulsion potential and which centers are subject to Brownian motion. Here, we add a stochastic birth-death process in the agent-based model, that approaches a logistic growth term in the continuum limit. We address the linear stability of the spatially homogeneous steady states of the macroscopic model and obtain a precise criterion for the phase transition, which links the system segregation ability to the model parameters. By comparing the criterion with the one obtained without logistic growth, we show that the system’s segregation ability is the result of a complex interplay between logistic growth, diffusion and mechanical repulsive interacti...

This are some notes on Statistical mechanics.
The topics are
-Recap of thermodynamics                                                     
-Thermodynamic of phase transitions                                                   
-recap of theory of ensamble                                                                               
-Statistical mechanics and phase transition                                                             
-Models (Ising in particular)                                                                                         
-Role of symmetry (symmetry breaking), dimension and range of interaction 
-Mean field theory (and Vann der Walls)                                                                   
-Landau Theory                     
-Ginzburg criterium
-Scaling theory (Windom)
-Renormalization group
-Symmetry breaking in other parts of physics (particles physics)

Introduction of interlath reverted austenite is an effective method to design ductile lath martensitic steels. The challenge in this concept is that all reverted austenite films have similar mechanical stability, hence, they all undergo transformation-induced plasticity (TRIP) at the same strain level. Here we propose a new thermo-mechanical treatment route to activate the TRIP effect over a broad strain regime and refer to it as 'spectral TRIP effect'. It aims at spreading the micro-mechanical stability of reverted austenite grains by widening the austenite nucleation barrier in martensite. To validate the proposed thermo-mechanical treatment route, an as-quenched medium-Mn martensitic steel was cold rolled prior to the reversion treatment at 600 C. Microstructure characterization was carried out by electron backscatter diffraction (EBSD) and electron channeling contrast imaging (ECCI). Mechanical tests show that the approach is effective. The spectral TRIP effect improves both, the strength and the ductility due to the well dispersed size distribution and the associated size-dependent deformation and phase transformation behavior of the reverted austenite grains, extending TRIP-related work hardening over a broad strain range.

An enthalpy formulation based fixed grid methodology is developed for the numerical solution of convection-diffusion controlled mushy region phase-change problems. The basic feature of the proposed method lies in the representation of the latent heat of evolution, and of the flow in the solid-liquid mushy zone, by suitably chosen sources. There is complete freedom within the me~odoIo~ for the definition of such sources so that a variety of phase-change situations can be modelled. A test problem of freezing in a thermal cavity under natural convection is used to demonstrate an application of the method.

During the last two decades our scientic group has developed new nonlinear methods of analysis applied to various physical systems. In this review study we present our scientic contribution to nonlinear science, including also some novel concepts as for the constructive role of complexity in modern physical theory. The experimental verification of chaos existence in physical systems remains one of the
most significant problems of non linear science and complexity. The extended chaotic algorithm presented in the following as well as the results concerning its application at different experimental time series reveal the universal character of the complexity theory for the far from equilibrium dynamics of spatially extended physical systems. The
developed methodology that was used compromises different types of computational tools as well as theoretical concepts for the physical interpretation of the experimental information. As we present here the strong dispute and criticism of chaos hypothesis in physical systems during the last two decades was fruitful and challenged us to develop a novel composition of experimental and theoretical knowledge of universal character for the far from equilibrium dynamics. The solar and magnetospheric dynamics included in space plasma processes, the environmental and seismic dynamics, the human brain or the on{chip workload are distinct systems which were studied by our group revealing common chaotic characteristics and chaotic phase transition
processes. Moreover, the intellectual struggle for the comprehension of the theoretical presuppositions of the experimentally observed universal chaotic character of spatially distributed systems lead us to the fundamentals of complexity theory as manifested at the macroscopic and microscopic level of physical reality. From this point of view, some common characteristics of macroscopic and microscopic complexity included in the scientific knowledge of the recent two or three decades can be used as a road for the physical theory unification. That is complexity, scaling, chaos, quanticity and
fractality could be supported as different manifestations of a unified physical law from the microscopic to the macroscopic and cosmological level. As we can argue, determinism and probabilism can also be unied through chaoticity. Moreover, the rising of new physical knowledge reveals that under the macroscopic or the microscopic
physical phenomena there exist a fundamental and multilevel acting unit physical process that produces physical reality rather than a fundamental essence or simple substance from which cosmos can be build.

Summary:
This chapter presents a descriptive and illustrative account of phase behavior in the seven naturally occurring petroleum fluids and ties all the known eleven phase-transition concepts in a unified narrative. The figures and tables contained in this report are designed so that they could effectively support the discussion about molecular make-up of petroleum fluids, P- and T-effects on phase behavior and phase transition points.
      Seven naturally occurring hydrocarbon fluids are known as petroleum fluids. They include, in the order of their fluidity, natural gas, gas condensate (or NGL), light crude, intermediate crude, heavy oil, tar sand and oil shale.  In this report we present a generalized description of the various phase transitions, which may occur in petroleum fluids with emphasis on heavy organics deposition. 
      At first the nature of every petroleum fluid is presented.  Their constituents including their so-called impurities are identified and categorized. Heavy fractions in petroleum fluids are discussed and their main families of constituents are presented including petroleum wax, diamondoids, asphaltenes and petroleum resins.  Then the generalized petroleum fluids phase behavior is discussed in light of the known theory of phase transitions. The effects of variations of composition, temperature and pressure on the phase behavior of petroleum fluids are introduced.  Finally eleven distinct phase-transition points of petroleum fluids are presented and their relation with state variables and constituents of petroleum fluids are identified.  This report is to generalize and relate phase behaviors of all the seven naturally occurring petroleum fluids into a unified perspective.  This work is the basis to develop a comprehensive computational model for phase behavior prediction of all the petroleum fluids, which is of major interest in the petroleum industry