Observation of the First Order Phase Change of SbSI

Block copolymers are composed of sequences of dissimilar chemical moieties covalently bonded together. If the block lengths of each component are sufficiently long and the blocks are thermodynamically incompatible, these materials are capable of undergoing microphase separation, a weak first-order phase transition which results in the formation of an ordered microstructural network. Most efforts designed to elucidate the phase and configurational behavior in these copolymers have focused on the simple AB and ABA designs. Few studies have thus far targeted the perfectly-alternating multiblock (AB)n architecture. In this work, two series of neat (AB)n copolymers have been synthesized from styrene and isoprene monomers at a composition of 50 wt% polystyrene (PS). In Set I, the total molecular weight is held constant while the number of AB block pairs (n) is increased from one to four (which results in shorter blocks). Set II consists of materials in which the block lengths are held constant and n is varied again from one to four (which results in longer chains). Transmission electron microscopy (TEM) has been employed here to investigate the morphologies and phase behavior of these materials and their blends.

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Surface ordering and destruction of the first order phase transition smectic A-smectic C* in free standing smectic films

Journal de Physique II ◽

10.1051/jp2:1994237 ◽

1994 ◽

Vol 4 (10) ◽

pp. 1865-1874 ◽

Cited By ~ 10

Author(s):

E. Demikhov ◽

U. Hoffmann ◽

H. Stegemeyer

Keyword(s):

Phase Transition ◽

Order Phase Transition ◽

Free Standing ◽

First Order ◽

Surface Ordering ◽

Smectic A ◽

Smectic C ◽

First Order Phase Transition ◽

First Order Phase

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Electric properties of olive oil under pressure

European Food Research and Technology ◽

10.1007/s00217-021-03761-7 ◽

2021 ◽

Author(s):

L. T. Pawlicki ◽

R. M. Siegoczyński ◽

S. Ptasznik ◽

K. Marszałek

Keyword(s):

Molecular Structure ◽

Phase Transition ◽

Phase Diagram ◽

Phase Transitions ◽

Olive Oil ◽

Material Parameters ◽

First Order ◽

Long Time ◽

Capacitive Reactance ◽

First Order Phase

AbstractThe main purpose of the experiment was a thermodynamic research with use of the electric methods chosen. The substance examined was olive oil. The paper presents the resistance, capacitive reactance, relative permittivity and resistivity of olive. Compression was applied with two mean velocities up to 450 MPa. The results were shown as functions of pressure and time and depicted on the impedance phase diagram. The three first order phase transitions have been detected. All the changes in material parameters were observed during phase transitions. The material parameters measured turned out to be the much more sensitive long-time phase transition factors than temperature. The values of material parameters and their dependence on pressure and time were compared with the molecular structure, arrangement of molecules and interactions between them. Knowledge about olive oil parameters change with pressure and its phase transitions is very important for olive oil production and conservation.

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Fate of false vacua in holographic first-order phase transitions

Journal of High Energy Physics ◽

10.1007/jhep12(2020)200 ◽

2020 ◽

Vol 2020 (12) ◽

Author(s):

Francesco Bigazzi ◽

Alessio Caddeo ◽

Aldo L. Cotrone ◽

Angel Paredes

Keyword(s):

Phase Transitions ◽

Chiral Symmetry ◽

Metastable Phase ◽

Chiral Symmetry Breaking ◽

Model Parameters ◽

Temperature Phase ◽

Thin Wall ◽

Critical Temperatures ◽

First Order ◽

First Order Phase

Abstract Using the holographic correspondence as a tool, we study the dynamics of first-order phase transitions in strongly coupled gauge theories at finite temperature. Considering an evolution from the large to the small temperature phase, we compute the nucleation rate of bubbles of true vacuum in the metastable phase. For this purpose, we find the relevant configurations (bounces) interpolating between the vacua and we compute the related effective actions. We start by revisiting the compact Randall-Sundrum model at high temperature. Using holographic renormalization, we compute the derivative term in the effective bounce action, that was missing in the literature. Then, we address the full problem within the top-down Witten-Sakai-Sugimoto model. It displays both a confinement/deconfinement and a chiral symmetry breaking/restoration phase transition which, depending on the model parameters, can happen at different critical temperatures. For the confinement/deconfinement case we perform the numerical analysis of an effective description of the transition and also provide analytic expressions using thick and thin wall approximations. For the chiral symmetry transition, we implement a variational approach that allows us to address the challenging non-linear problem stemming from the Dirac-Born-Infeld action.

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