Heat capacities and volumes of NaCl, MgCl2, CaCl2, and NiCl2 up to 6 molal in water

1981 ◽  
Vol 59 (21) ◽  
pp. 3049-3054 ◽  
Author(s):  
Gèrald Perron ◽  
Alain Roux ◽  
Jacques E. Desnoyers
Keyword(s):  
Aqueous Solutions ◽  
Long Range ◽  
Higher Order ◽  
Heat Capacities ◽  
Range Order ◽  
Long Range Order ◽  
High Concentration ◽  
Concentration Region ◽  
Partial Molar Heat Capacities ◽  
High Concentrations

It has been claimed by Enderby and co-workers that changes in long-range order occur in NiCl2 aqueous solutions at high concentrations. To investigate the possibility of a transition, the partial molar heat capacities and volumes of NiCl2, CaCl2, MgCl2, and NaCl were measured and compared in water at 25 °C up to 6 mol kg−1. In the case of NaCl, data were also measured at 5 and 45 °C. A slight change in slope of [Formula: see text] is observed for NiCl2 around 4 mol kg−1 which may suggest a third or higher order transition. However, the change is too small to support unambiguously any particular model for the high concentration region.

scholarly journals Light-responsive self-assembly of a cationic azobenzene surfactant at high concentration

Soft Matter ◽  
2020 ◽  
Vol 16 (40) ◽  
pp. 9183-9187
Author(s):  
Camille Blayo ◽  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Nikul Khunti ◽  
Nathan P. Cowieson ◽  
...  
Keyword(s):  
Long Range ◽  
Uv Irradiation ◽  
Self Assembly ◽  
Optical Anisotropy ◽  
Range Order ◽  
Long Range Order ◽  
High Concentration ◽  
Self Assembled ◽  
High Concentrations

A cationic azobenzene photosurfactant (AzoTAB) forms self-assembled structures with long-range order and optical anisotropy at high concentrations. These high-concentration mesophases are lost or disrupted with UV irradiation.

Liquid crystal phases of self-assembled amphiphilic aggregates

1993 ◽  
Vol 344 (1672) ◽  
pp. 357-375 ◽  
Keyword(s):  
Long Range ◽  
Range Order ◽  
Long Range Order ◽  
Self Assembling ◽  
Ordered Phases ◽  
Aggregate Morphology ◽  
Aggregate Growth ◽  
Nematic Phases ◽  
High Concentrations ◽  
Concentrated Solution

Long-range order in solutions of reversibly self-assembling molecules results from interactions among the asymmetric aggregates. Even for electrically neutral species, repulsions between the aggregates become significant at high concentrations. At the very least, the excluded volume of asymmetric aggregates creates formidable packing constraints which are relieved by orientational and positional alignment. Aggregate growth thus promotes long-range order, and long-range order facilitates growth. Nematic phases occur if aggregate growth is strong enough to induce orientational ordering at concentrations lower than those that induce positional ordering. The symmetry of the positionally ordered phases reflects aggregate morphology: the polydispersity of aggregates that grow in one (two) dimension(s) to form rod-like (plate-like) particles suppresses the smectic (columnar) phase in favour of the columnar (smectic) phase. Because plate-like aggregates pack more easily than rod-like aggregates, increasing concentration induces a rearrangement from rod-like to plate-like aggregates, and a transition from columnar to smectic ordering, in solutions of molecules, such as surfactants, capable of forming both types of aggregates. In mixtures of aggregating and non-aggregating species, the difficulty of packing spherically shaped particles among elongated particles results in dramatic demixing such that a very concentrated solution of very large, highly aligned aggregates coexists with a relatively dilute solution depleted of the aggregating species.

Superfluidity and Superconductivity

2018 ◽  
Author(s):  
Norman J. Morgenstern Horing
Keyword(s):  
Magnetic Field ◽  
Wave Function ◽  
Wave Packet ◽  
Long Range ◽  
Cooper Pair ◽  
Bose Condensation ◽  
Range Order ◽  
Condensed State ◽  
Long Range Order ◽  
Coherent Wave

Chapter 13 addresses Bose condensation in superfluids (and superconductors), which involves the field operator ψ‎ having a c-number component (<ψ(x,t)>≠0), challenging number conservation. The nonlinear Gross-Pitaevskii equation is derived for this condensate wave function<ψ>=ψ−ψ˜, facilitating identification of the coherence length and the core region of vortex motion. The noncondensate Green’s function G˜1(1,1′)=−i<(ψ˜(1)ψ˜+(1′))+> and the nonvanishing anomalous correlation function F˜∗(2,1′)=−i<(ψ˜+(2)ψ˜+(1′))+> describe the dynamics and elementary excitations of the non-condensate states and are discussed in conjunction with Landau’s criterion for viscosity. Associated concepts of off-diagonal long-range order and the interpretation of <ψ> as a superfluid order parameter are also introduced. Anderson’s Bose-condensed state, as a phase-coherent wave packet superposition of number states, resolves issues of number conservation. Superconductivity involves bound Cooper pairs of electrons capable of Bose condensation and superfluid behavior. Correspondingly, the two-particle Green’s function has a term involving a product of anomalous bound-Cooper-pair condensate wave functions of the type F(1,2)=−i<(ψ(1)ψ(2))+>≠0, such that G2(1,2;1′,2′)=F(1,2)F+(1′,2′)+G˜2(1,2;1′,2′). Here, G˜2 describes the dynamics/excitations of the non-superfluid-condensate states, while nonvanishing F,F+ represent a phase-coherent wave packet superposition of Cooper-pair number states and off-diagonal long range order. Employing this form of G2 in the G1-equation couples the condensed state with the non-condensate excitations. Taken jointly with the dynamical equation for F(1,2), this leads to the Gorkov equations, encompassing the Bardeen–Cooper–Schrieffer (BCS) energy gap, critical temperature, and Bogoliubov-de Gennes eigenfunction Bogoliubons. Superconductor thermodynamics and critical magnetic field are discussed. For a weak magnetic field, the Gorkov-equations lead to Ginzburg–Landau theory and a nonlinear Schrödinger-like equation for the pair wave function and the associated supercurrent, along with identification of the Cooper pair density. Furthermore, Chapter 13 addresses the apparent lack of gauge invariance of London theory with an elegant variational analysis involving re-gauging the potentials, yielding a manifestly gauge invariant generalization of the London equation. Consistency with the equation of continuity implies the existence of Anderson’s acoustic normal mode, which is supplanted by the plasmon for Coulomb interaction. Type II superconductors and the penetration (and interaction) of quantized magnetic flux lines are also discussed. Finally, Chapter 13 addresses Josephson tunneling between superconductors.

Time-Resolved, Laser-Induced Phase Transformation in Aluminum

1984 ◽  
Vol 35 ◽  
Author(s):  
S. Williamson ◽  
G. Mourou ◽  
J.C.M. Li
Keyword(s):  
Point Defect ◽  
Long Range ◽  
Rapid Heating ◽  
Range Order ◽  
Nucleation Theory ◽  
Long Range Order ◽  
Time Resolved ◽  
Aluminum Films ◽  
Thin Aluminum ◽  
Initial Nucleus

ABSTRACTThe technique of picosecond electron diffraction is used to time resolve the laser-induced melting of thin aluminum films. It is observed that under rapid heating conditions, the long range order of the lattice subsists for lattice temperatures well above the equilibrium point, indicative of superheating. This superheating can be verified by directly measuring the lattice temperature. The collapse time of the long range order is measured and found to vary from 20 ps to several nanoseconds according to the degree of superheating. Two interpretations of the delayed melting are offered, based on the conventional nucleation and point defect theories. While the nucleation theory provides an initial nucleus size and concentration for melting to occur, the point defect theory offers a possible explanation for how the nuclei are originally formed.

scholarly journals Finite temperature off-diagonal long-range order for interacting bosons

2020 ◽  
Vol 102 (18) ◽  
Author(s):  
A. Colcelli ◽  
N. Defenu ◽  
G. Mussardo ◽  
A. Trombettoni
Keyword(s):  
Long Range ◽  
Finite Temperature ◽  
Range Order ◽  
Long Range Order
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