A query on crystallization temperature-dependent cooling function under nonisothermal condition

2006 ◽  
Vol 44 (5) ◽  
pp. 795-800 ◽  
Author(s):  
Yonggang Shangguan ◽  
Yihu Song ◽  
Qiang Zheng
Keyword(s):  
Crystallization Temperature ◽  
Nonisothermal Condition ◽  
Temperature Dependent ◽  
Cooling Function

Crystallization Temperature-Dependent Crystal Orientations within Nanoscale Confined Lamellae of a Self-Assembled Crystalline−Amorphous Diblock Copolymer

2000 ◽  
Vol 122 (25) ◽  
pp. 5957-5967 ◽  
Author(s):  
Lei Zhu ◽  
Stephen Z. D. Cheng ◽  
Bret H. Calhoun ◽  
Qing Ge ◽  
Roderic P. Quirk ◽  
...  
Keyword(s):  
Diblock Copolymer ◽  
Crystallization Temperature ◽  
Temperature Dependent ◽  
Crystal Orientations ◽  
Self Assembled

Stress Limited Scaling of Ge2Sb2Te5

2010 ◽  
Vol 1251 ◽  
Author(s):  
Robert Edward Simpson ◽  
Milos Krbal ◽  
Paul Fons ◽  
Alex Kolobov ◽  
Tomoya Uruga ◽  
...  
Keyword(s):  
Phase Change ◽  
Compressive Stress ◽  
Crystallization Temperature ◽  
Temperature Dependent ◽  
Dominant Effect ◽  
X Ray ◽  
Bulk Crystallization ◽  
Crystallisation Temperature

AbstractThe influence of stress on the phase change behaviour of Ge2Sb2Te5 encapsulated by ZnS-SiO2 and TiN is investigated using temperature dependent Extended X-ray Asbsorption Fines Structure and Ellipsometry to determine the crystallisation temperature. The encapsulation material surrounding the Ge2Sb2Te5 has an increasingly dominant effect on the material's ability to change phase and can cause a profound increase in its crystallization temperature. We have experimentally shown that the increased crystallization temperature originates from compressive stress exerted from the encapsulation material. By minimizing the stress we have maintained the bulk crystallization temperature in Ge2Sb2Te5 films just 2 nm thick.

scholarly journals Cooling and instabilities in colliding flows

2021 ◽  
Author(s):  
R N Markwick ◽  
A Frank ◽  
J Carroll-Nellenback ◽  
B Liu ◽  
E G Blackman ◽  
...  
Keyword(s):  
Thermal Instability ◽  
Three Dimensional ◽  
Oscillation Period ◽  
Three Dimensions ◽  
Temperature Dependent ◽  
Radiative Shock ◽  
Hydrodynamic Simulations ◽  
Protostellar Jets ◽  
The One ◽  
Cooling Function

Abstract Collisional self-interactions occurring in protostellar jets give rise to strong shocks, the structure of which can be affected by radiative cooling within the flow. To study such colliding flows, we use the AstroBEAR AMR code to conduct hydrodynamic simulations in both one and three dimensions with a power law cooling function. The characteristic length and time scales for cooling are temperature dependent and thus may vary as shocked gas cools. When the cooling length decreases sufficiently rapidly the system becomes unstable to the radiative shock instability, which produces oscillations in the position of the shock front; these oscillations can be seen in both the one and three dimensional cases. Our simulations show no evidence of the density clumping characteristic of a thermal instability, even when the cooling function meets the expected criteria. In the three-dimensional case, the nonlinear thin shell instability (NTSI) is found to dominate when the cooling length is sufficiently small. When the flows are subjected to the radiative shock instability, oscillations in the size of the cooling region allow NTSI to occur at larger cooling lengths, though larger cooling lengths delay the onset of NTSI by increasing the oscillation period.

scholarly journals Pressure- and Temperature-Dependent Crystallization Kinetics of Isotactic Polypropylene under Process Relevant Conditions

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1138
Author(s):  
Yvonne Spoerer ◽  
Regine Boldt ◽  
René Androsch ◽  
Ines Kuehnert
Keyword(s):  
Injection Molding ◽  
Cooling Rate ◽  
Crystallization Kinetics ◽  
Crystallization Temperature ◽  
Random Copolymer ◽  
Shift Factor ◽  
Temperature Dependent ◽  
Chip Calorimetry ◽  
The Relationship ◽  
Kinetics Of

In this study, a non-nucleated homopolymer (HP) and random copolymer (RACO), as well as a nucleated HP and heterophasic copolymer (HECO) were investigated regarding their crystallization kinetics. Using pvT-measurements and fast scanning chip calorimetry (FSC), the crystallization behavior was analyzed as a function of pressure, cooling rate and temperature. It is shown that pressure and cooling rate have an opposite influence on the crystallization temperature of the materials. Furthermore, the addition of nucleating agents to the material has a significant effect on the maximum cooling rate at which the formation of α-crystals is still possible. The non-nucleated HP and RACO materials show significant differences that can be related to the sterically hindering effect of the comonomer units of RACO on crystallization, while the nucleated materials HP and HECO show similar crystallization kinetics despite their different structures. The pressure-dependent shift factor of the crystallization temperature is independent of the material. The results contribute to the description of the relationship between the crystallization kinetics of the material and the process parameters influencing the injection-molding induced morphology. This is required to realize process control in injection molding in order to produce pre-defined morphologies and to design material properties.

(111) Monocrystalline Nickel Films

1972 ◽  
Vol 30 ◽  
pp. 512-513
Author(s):  
T.E. Pratt ◽  
R.W. Vook
Keyword(s):  
Film Thickness ◽  
Deposition Rate ◽  
Room Temperature ◽  
Narrow Range ◽  
High Vacuum ◽  
Residual Pressure ◽  
Temperature Dependent ◽  
Deposition Parameters ◽  
Transmission Electron ◽  
Substrate Temperatures

(111) oriented thin monocrystalline Ni films have been prepared by vacuum evaporation and examined by transmission electron microscopy and electron diffraction. In high vacuum, at room temperature, a layer of NaCl was first evaporated onto a freshly air-cleaved muscovite substrate clamped to a copper block with attached heater and thermocouple. Then, at various substrate temperatures, with other parameters held within a narrow range, Ni was evaporated from a tungsten filament. It had been shown previously that similar procedures would yield monocrystalline films of CU, Ag, and Au.For the films examined with respect to temperature dependent effects, typical deposition parameters were: Ni film thickness, 500-800 A; Ni deposition rate, 10 A/sec.; residual pressure, 10-6 torr; NaCl film thickness, 250 A; and NaCl deposition rate, 10 A/sec. Some additional evaporations involved higher deposition rates and lower film thicknesses.Monocrystalline films were obtained with substrate temperatures above 500° C. Below 450° C, the films were polycrystalline with a strong (111) preferred orientation.

The reaction of amorphous Ni-Nb films with Si in the presence of a native SiO2 layer

1990 ◽  
Vol 48 (4) ◽  
pp. 664-665
Author(s):  
N. Rozhanski ◽  
A. Barg
Keyword(s):  
High Temperature ◽  
Crystallization Temperature ◽  
Diffusion Barriers ◽  
Sio2 Layer ◽  
Si Substrate ◽  
Cross Sectional ◽  
Plan View ◽  
Temperature Range ◽  
Sputter Deposited

Amorphous Ni-Nb alloys are of potential interest as diffusion barriers for high temperature metallization for VLSI. In the present work amorphous Ni-Nb films were sputter deposited on Si(100) and their interaction with a substrate was studied in the temperature range (200-700)°C. The crystallization of films was observed on the plan-view specimens heated in-situ in Philips-400ST microscope. Cross-sectional objects were prepared to study the structure of interfaces.The crystallization temperature of Ni5 0 Ni5 0 and Ni8 0 Nb2 0 films was found to be equal to 675°C and 525°C correspondingly. The crystallization of Ni5 0 Ni5 0 films is followed by the formation of Ni6Nb7 and Ni3Nb nucleus. Ni8 0Nb2 0 films crystallise with the formation of Ni and Ni3Nb crystals. No interaction of both films with Si substrate was observed on plan-view specimens up to 700°C, that is due to the barrier action of the native SiO2 layer.

Scanning Transmission Electron Microscopy of Polyethylene Crystals

1980 ◽  
Vol 38 ◽  
pp. 242-245
Author(s):  
F. Khoury ◽  
L. H. Bolz
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Crystallization Temperature ◽  
Scanning Transmission Electron Microscopy ◽  
Growth Habit ◽  
Lateral Growth ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Growth Habits

The lateral growth habits and non-planar conformations of polyethylene crystals grown from dilute solutions (<0.1% wt./vol.) are known to vary depending on the crystallization temperature.1-3 With the notable exception of a study by Keith2, most previous studies have been limited to crystals grown at <95°C. The trend in the change of the lateral growth habit of the crystals with increasing crystallization temperature (other factors remaining equal, i.e. polymer mol. wt. and concentration, solvent) is illustrated in Fig.l. The lateral growth faces in the lozenge shaped type of crystal (Fig.la) which is formed at lower temperatures are {110}. Crystals formed at higher temperatures exhibit 'truncated' profiles (Figs. lb,c) and are bound laterally by (110) and (200} growth faces. In addition, the shape of the latter crystals is all the more truncated (Fig.lc), and hence all the more elongated parallel to the b-axis, the higher the crystallization temperature.

Temperature-dependent translational regulation of the ER omega-3 fatty acid desaturase gene in wheat root tips

2000 ◽  
Vol 24 (6) ◽  
pp. 805-813 ◽  
Author(s):  
Gorou Horiguchi ◽  
Takuichi Fuse ◽  
Naoto Kawakami ◽  
Hiroaki Kodama ◽  
Koh Iba
Keyword(s):  
Fatty Acid ◽  
Translational Regulation ◽  
Fatty Acid Desaturase ◽  
Wheat Root ◽  
Omega 3 ◽  
Root Tips ◽  
Temperature Dependent ◽  
Desaturase Gene ◽  
Omega 3 Fatty Acid ◽  
Fatty Acid Desaturase Gene

Studies on the Temperature Dependent Fluorescence of Poly-N-Vinylcarbazole Films up to the Glass Transition: Role of the Excimer Forming Sites

1988 ◽  
Vol 156 (1) ◽  
pp. 319-329 ◽  
Author(s):  
Gabriele Giro ◽  
Piergiulio Di Marco ◽  
Francesco Barigelletti
Keyword(s):  
Glass Transition ◽  
Temperature Dependent

Marangoni convection induced by a nonlinear temperature-dependent surface tension

1986 ◽  
Vol 47 (1) ◽  
pp. 23-29 ◽  
Author(s):  
A. Cloot ◽  
G. Lebon
Keyword(s):  
Surface Tension ◽  
Marangoni Convection ◽  
Temperature Dependent ◽  
Nonlinear Temperature
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