Crystallization behavior of a confined CuZr metallic liquid film with a sandwich-like structure

2019 ◽  
Vol 21 (25) ◽  
pp. 13738-13745
Author(s):  
Yunrui Duan ◽  
Jie Li ◽  
Xingfan Zhang ◽  
Tao Li ◽  
Hamidreza Arandiyan ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Liquid Film ◽  
Crystallization Behavior ◽  
Metallic Liquid ◽  
Crystal Transition

The liquid-to-crystal transition temperature and interatomic repulsion softness reach maxima as a function of wall–wall separation when a new layer starts to form.

scholarly journals Dewetting Properties of Metallic Liquid Film on Nanopillared Graphene

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiongying Li ◽  
Yezeng He ◽  
Yong Wang ◽  
Jichen Dong ◽  
Hui Li
Keyword(s):  
Liquid Film ◽  
Metallic Liquid

scholarly journals ANALISIS SIFAT TERMAL DAN UJI KELARUTAN DARI KARET ALAM SIKLIS DAN KARET ALAM CAIR SIKLIS

2018 ◽  
Vol 16 (1) ◽  
pp. 36
Author(s):  
Leni Widiarti ◽  
Basuki Wirjosentono ◽  
Eddyanto Eddyanto
Keyword(s):  
Thermal Analysis ◽  
Transition Temperature ◽  
Natural Rubber ◽  
Oxidative Degradation ◽  
Melting Transition ◽  
Scanning Calorimetry ◽  
Solubility Test ◽  
Polarity Index ◽  
Liquid Natural Rubber ◽  
Crystal Transition

Abstract. The research has done analysis of thermal properties and solubility test of Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR). Cyclic Liquid Natural Rubber (CLNR) is a cyclical natural rubber which has decreased molecular weight. Synthesis of Cyclic Liquid Natural Rubber (CLNR) do by oxidative degradation after cyclic.  Oxidative degradation after cyclic using Cyclic Natural Rubber (CNR) and phenylhydrazine reagent with flow rate 2 LMin-1 of oxygen atmosphere during 24 hours. Thermal analysis of Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR) by Differential Scanning Calorimetry (DSC),the glass transition temperature (Tg) of Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR) are 102,82  o C and 103,67 o C, the crystal transition temperature (Tc) of Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR) are 362,45 o C and 330,29 o C and the melting transition temperature ( Tm) of Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR) are 509,24 o C and 440,00 o C. Solubility test by dilute Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR) in some solvent with different properties and polarity index. Solubility test shows the results Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR)  has polarity index around 2,4 – 4,4 and 2,4 and 4,4.               Keywords: CLNR, CNR, oxidative degradation

scholarly journals Strain-Induced Form Transition and Crystallization Behavior of the Transparent Polyamide

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1028
Author(s):  
Chenxu Zhou ◽  
Siyuan Dong ◽  
Ping Zhu ◽  
Jiguang Liu ◽  
Dujin Wang ◽  
...  
Keyword(s):  
Crystalline Structure ◽  
Crystallization Behavior ◽  
Heating Process ◽  
Stable Form ◽  
X Ray Diffraction ◽  
Preparation Methods ◽  
Strain Induced Crystallization ◽  
Crystal Transition ◽  
Stretching Deformation ◽  
Induced Crystallization

A transparent polyamide, poly(4,4′-aminocyclohexyl methylene dodecanedicarboxylamide) (PAPACM12), was studied and characterized by in situ wide-angle X-ray diffraction (WAXD) to establish the relationship between its crystallization behavior, crystalline form transition under external fields, and macroscopic properties. During the heating process, cold crystallization occurred and increased, and there was no form transition below the melting point. During the isothermal process, PAPACM12 exhibited the same crystalline structure as that during the heating process. The crystalline structure of PAPACM12 was attributed to α-form crystal, which is the stable form, according to the WAXD diffraction peaks of the conventional AABB-type polyamides. During stretching deformation, the crystal transition from α-form to γ-form and strain-induced crystallization were observed to contribute to the PAPACM12 with higher breaking strength and elongation. This study firstly determine the crystalline structure of transparent polyamides, and then the controlled strain-induced crystallization and transformation are demonstrated to be effective preparation methods for polyamides with high properties.

scholarly journals Research on Sulfate Attack Mechanism of Cement Concrete Based on Chemical Thermodynamics

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Peng Liu ◽  
Ying Chen ◽  
Zhiwu Yu ◽  
Lingkun Chen ◽  
Yongfeng Zheng
Keyword(s):  
Phase Composition ◽  
Transition Temperature ◽  
Slenderness Ratio ◽  
Crystal Form ◽  
Sulfate Attack ◽  
Ion Concentration ◽  
Chemical Thermodynamics ◽  
Sulfate Ion ◽  
Cement Concrete ◽  
Crystal Transition

Based on principles of chemical thermodynamics, the relationship between temperature and the Gibbs free energy of erosion products generated during the sulfate attack on cement concrete was deduced. The orientation of chemical reactions of sulfate attack on cement concrete was theoretically determined as well as the critical sulfate ion concentration and the formation conditions of erosion products. The phase composition, microstructure, crystal form, and morphology of erosion products before and after sulfate attack were investigated by environmental scanning electron microscope and energy spectrum analysis (ESEM-EDS) and X-ray diffraction (XRD). The results show that the effects of sulfate ion concentration and temperature on cement concrete sulfate attack are significant, and different influencing factors correlate with each other. The crystal transition temperature between the anhydrite and dihydrate gypsum is 42°C, and the corresponding concentration of sulfate ion is about 2.3 × 10−3 mol/L. Simultaneously, the crystal transition temperature between the thenardite and mirabilite is 32.4°C. Moreover, the theoretical upper limit temperature and sulfate ion lower limit concentration of thaumasite are 44°C and 0.0023 mol/L, respectively. The ESEM-EDS and XRD results imply that the chemical thermodynamics can be used to reveal the erosion mechanism of sulfate attack on cement concrete. The major erosion products of sulfate attack on cement concrete are rod-like ettringite with a larger slenderness ratio, plate-like gypsum, granular sulfate salt, incompletely corroded calcium hydroxide, and residual skeleton of calcium silicate hydrate. The sulfate attack has double effects on mechanical properties of specimens, which can affect the microstructure, phase composition, type, and morphology of erosion products.

Synthesis, Crystallization Behavior and Surface Modification of Ni-Cr-Si-Fe Amorphous Alloy

2012 ◽  
Vol 510-511 ◽  
pp. 137-142 ◽  
Author(s):  
Muhammad Iqbal ◽  
J.I. Akhter ◽  
M.U. Rajput ◽  
K. Mahmood ◽  
Z. Hussain ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Surface Modification ◽  
Glass Transition ◽  
Transition Temperature ◽  
Crystallization Behavior ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Scanning Calorimetry ◽  
Scanning Electron

A quaternary Ni86Cr7Si4Fe3 amorphous alloy was synthesized by melt spinning technique. Surface modification was done by electron beam melting (EBM), neutron irradiation and γ-rays. Microstructure of as cast, annealed and modified samples was examined by scanning electron microscope. Crystallization behavior was studied by annealing the samples in vacuum at different temperatures in the range 773-1073 K. Techniques of X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used for characterization. Differential scanning calorimetry (DSC) was conducted at various heating rates in the range 10-40 K/min. Thermal parameters like glass transition temperature Tg, crystallization temperature Tx, supercooled liquid region ΔTx and reduced glass transition temperature Trg were measured. The Ni86Cr7Si4Fe3 alloy exhibits wide supercooled liquid region of 60 K indicating good thermal stability. The activation energy was calculated to be 160±4 kJ/mol using Kissinger and Ozawa equations respectively which indicates high resistance against crystallization. The XRD results of the samples annealed at 773 K, 923 K, 973 K and 1073 K/20 min show nucleation of Ni2Cr3 and NiCrFe crystalline phases. Vickers microhardness of the as cast ribbon was measured to be 680.. About 30-50 % increase in hardness was achieved by applying EBM technique.

In situ Tensile Experiments at Low Temperatures on Niobium Single Crystals by H.V.E.M.

1975 ◽  
Vol 33 ◽  
pp. 58-59
Author(s):  
F. H. Louchet ◽  
L. P. Kubin
Keyword(s):  
Electron Microscope ◽  
Transition Temperature ◽  
Low Temperature ◽  
Slip System ◽  
Low Temperatures ◽  
Tensile Axis ◽  
Image Intensifier ◽  
Screw Dislocations ◽  
Source Operation

Experiments have been carried out on the 3 MeV electron microscope in Toulouse. The low temperature straining holder has been previously described Images given by an image intensifier are recorded on magnetic tape.The microtensile niobium samples are cut in a plane with the two operative slip directions [111] and lying in the foil plane. The tensile axis is near [011].Our results concern:- The transition temperature of niobium near 220 K: at this temperature and below an increasing difference appears between the mobilities of the screw and edge portions of dislocations loops. Source operation and interactions between screw dislocations of different slip system have been recorded.

The structure of membranes and membrane proteins embedded in amorphous ice

1992 ◽  
Vol 50 (1) ◽  
pp. 432-433
Author(s):  
Uwe Lücken ◽  
Joachim Jäger
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Membrane Proteins ◽  
Phase Transition Temperature ◽  
Lipid Vesicles ◽  
Freezing Stress ◽  
Amorphous Ice ◽  
Different Temperatures ◽  
Band Pass ◽  
Lipid Polymorphism

TEM imaging of frozen-hydrated lipid vesicles has been done by several groups Thermotrophic and lyotrophic polymorphism has been reported. By using image processing, computer simulation and tilt experiments, we tried to learn about the influence of freezing-stress and defocus artifacts on the lipid polymorphism and fine structure of the bilayer profile. We show integrated membrane proteins do modulate the bilayer structure and the morphology of the vesicles.Phase transitions of DMPC vesicles were visualized after freezing under equilibrium conditions at different temperatures in a controlled-environment vitrification system. Below the main phase transition temperature of 24°C (Fig. 1), vesicles show a facetted appearance due to the quasicrystalline areas. A gradual increase in temperature leads to melting processes with different morphology in the bilayer profile. Far above the phase transition temperature the bilayer profile is still present. In the band-pass-filtered images (Fig. 2) no significant change in the width of the bilayer profile is visible.

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