scholarly journals Variation along liquid isomorphs of the driving force for crystallization

2017 ◽  
Vol 2 (3) ◽  
Author(s):  
Ulf Pedersen ◽  
Karolina Adrjanowicz ◽  
Kristine Niss ◽  
Nicholas Bailey
Keyword(s):  
Experimental Data ◽  
Relaxation Time ◽  
Driving Force ◽  
Supercooled Liquid ◽  
Scaling Exponent ◽  
Dimethyl Phthalate ◽  
Molecular Liquids ◽  
Lennard Jones ◽  
Structure And Dynamics ◽  
Increasing Function

We investigate the variation of the driving force for crystallization of a supercooled liquid along isomorphs, curves along which structure and dynamics are invariant. The variation is weak, and can be predicted accurately for the Lennard-Jones fluid using a recently developed formalism and data at a reference temperature. More general analysis allows interpretation of experimental data for molecular liquids such as dimethyl phthalate and indomethacin, and suggests that the isomorph scaling exponent \gammaγ in these cases is an increasing function of density, although this cannot be seen in measurements of viscosity or relaxation time.

scholarly journals Ignition Vulnerabilities of Combustibles around Houses to Firebrand Showers: Further Comparison of Experiments

2021 ◽  
Vol 13 (4) ◽  
pp. 2136
Author(s):  
Sayaka Suzuki ◽  
Samuel L. Manzello
Keyword(s):  
Experimental Data ◽  
Thermal Radiation ◽  
Driving Force ◽  
Fire Spread ◽  
Significant Problem ◽  
Next Generation ◽  
Similar Time ◽  
Comparison Of Experiments ◽  
Fire Front ◽  
Wui Fires

Wildland fires and wildland urban-interface (WUI) fires have become a significant problem in recent years. The mechanisms of home ignition in WUI fires are direct flame contact, thermal radiation, and firebrand attack. Out of these three fire spread factors, firebrands are considered to be a main driving force for rapid fire spread as firebrands can fly far from the fire front and ignite structures. The limited experimental data on firebrand showers limits the ability to design the next generation of communities to resist WUI fires to these types of exposures. The objective of this paper is to summarize, compare, and reconsider the results from previous experiments, to provide new data and insights to prevent home losses from firebrands in WUI fires. Comparison of different combustible materials around homes revealed that wood decking assemblies may be ignited within similar time to mulch under certain conditions.

scholarly journals The Formation of Deposits on the Walls of the Pores in the Filtering Process

2019 ◽  
Vol 14 (2) ◽  
pp. 15-22
Author(s):  
Yu. A. Taran ◽  
A. V. Kozlov ◽  
A. L. Taran
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Driving Force ◽  
Nonequilibrium Thermodynamics ◽  
Driving Forces ◽  
Solid Particles ◽  
Original Structure ◽  
Small Particles ◽  
Filtration Process ◽  
Filter Unit

The aim of the work is to consider the mechanism of clogging the pores of the filter unit by small particles from the flow of filtrate inside them. Theoretical ideas about the process of filtering with the deposition of small particles from the filtrate on the pore walls and attribution of its fundamentals to restructuring from the original structure to the final structure allow to describe the process of clogging the pores using well studied concepts of known processes with phase transformations (in particular, crystallization). Based on this analogy and the approach to the description of the transformation of the "old" structure into a "new" one in time, using experimental data and their processing we calculated the rate of nucleation of the sediment centers (ωnucl), the linear (υlin) and volumetric rates of sediment plaques growth in the pores of the filter unit at different values of the process driving force, at different pressure difference in the system, and at different concentrations of solid particles in the suspension. Interpolation and extrapolation dependences were obtained for analyzing the mechanisms of sediments formation and growth for determining and calculating these (ωnucl, υlin) rates. Using the concepts of nonequilibrium thermodynamics to assess the influence of the driving forces we studied their influence (changes in the concentration of solid particles in the filtrate suspension and pressure drop across the filtering layer) on the dynamics of the filtration process. Using the data obtained it is possible to find the degree of clogging of through pores, which determines the filtration conditions, the filter septum type, and the filter overall dimensions.

APPLICATION OF REED-VIBRATION MECHANICAL SPECTROSCOPY FOR LIQUIDS IN STUDYING LIQUID CRYSTALLIZATION

2013 ◽  
Vol 27 (21) ◽  
pp. 1350080 ◽  
Author(s):  
HENG-WEI ZHOU ◽  
LI-NA WANG ◽  
LI-LI ZHANG ◽  
YI-NENG HUANG
Keyword(s):  
Glass Transition ◽  
Room Temperature ◽  
Crystallization Process ◽  
Volume Fraction ◽  
Supercooled Liquid ◽  
Avrami Exponent ◽  
Dimethyl Phthalate ◽  
Mechanical Spectroscopy ◽  
Crystal Volume ◽  
Complex Young’S Modulus

By using the reed-vibration mechanical spectroscopy for liquids (RMS-L), we measured the complex Young's modulus of dimethyl phthalate (DP) during a cooling and heating circulation starting from room temperature at about 2 KHz. The results show that there is no crystallization in the cooling supercooled liquid (CSL) of DP, but a crystallization process in the heating supercooled liquid (HSL) after the reverse glass transition. Based on the measured modulus, crystal volume fraction (v) during the HSL crystallization was calculated. Moreover, the Avrami exponent (n) was obtained according to the JJMA equation and v data. In view of n versus temperature and v, the nucleation dynamics was analyzed, and especially, there has already existed saturate nuclei in DP HSL before the crystallization. Furthermore, the authors inferred that the nuclei are induced by the random frozen stress in the glass, but there is no nucleus in CSL. The above results indicated that RMS-L might provide a new way to measure and analyze the crystallization of liquids.

Structure and dynamics of Lennard-Jones clusters with impurities

1989 ◽  
Vol 12 (1-4) ◽  
pp. 81-83 ◽  
Author(s):  
I. L. Garz�n ◽  
X. P. Long ◽  
R. Kawai ◽  
J. H. Weare
Keyword(s):  
Lennard Jones ◽  
Structure And Dynamics

Vibrational Dephasing and Collision Induced Scattering in Molecular Liquids

1983 ◽  
Vol 22 ◽  
Author(s):  
Jiri Jonas
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Temperature Effects ◽  
Essential Role ◽  
Theoretical Models ◽  
Molecular Liquids ◽  
Vibrational Dephasing

ABSTRACTThe results of several Raman studies of vibrational dephasing in polyatomic molecular liquids at high pressure are reviewed. The density and temperature effects on vibrational dephasing of isotropic Raman bands for different vibrational models are reported for the following liquids: C(CH3)4; Si(CH3)4; Ge(CH3)4; ; Sn(CH3)4 and isobutylene CH2; = C(CH3) 2.The experimental data are used to test the current theoretical models of vibrational dephasing. Selected results of our high pressure experiments on collision induced scattering in polyatomic molecular liquids demonstrate well the essential role of high pressure in studying these phenomena.

scholarly journals Predicting How Nanoconfinement Changes the Relaxation Time of a Supercooled Liquid

2013 ◽  
Vol 111 (23) ◽  
Author(s):  
Trond S. Ingebrigtsen ◽  
Jeffrey R. Errington ◽  
Thomas M. Truskett ◽  
Jeppe C. Dyre
Keyword(s):  
Relaxation Time ◽  
Supercooled Liquid
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