نتایج جستجو برای: crystallization half time

تعداد نتایج: 2056028  

In order to improve the traditional freezing crystallization process of calcium nitrate in nitric phosphate process, crystal growth experiments by adding Ca(NO3)2·4H2O seeds in supersaturated calcium nitrate solution in a Circulating Fluidized Bed (CFB) crystallizer were carried out on crystal growth kinetics. The results showed that the growth of C...

2003
Annamaria Celli Edgar D. Zanotto Isak Avramov

We studied nucleation and crystal growth in two polypropylene samples by analyzing the number of spherulites, their size, and shape for various treatments in a hot-stage microscope. The consistency of nucleation and growth data were tested by using overall crystallization experiments and the Jonhson–Mehl–Avrami–Kolmogorov Q1 equation. In isothermal conditions, for temperatures, TC, varying betw...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2007
amir abbas izadpanah mohsen vafaie sefti farshad varaminian

based on driving force for crystallization of one-component gas hydrate, in this report an expression for the supersaturation for crystallization of multicomponent gas hydrate is derived. expressions for the supersaturation are obtained in isothermal and isobaric regimes. the results obtained are applied to the crystallization of hydrates of mixtures of methane plus ethane and can apply to othe...

2004
Andrzej Katrusiak Armand Budzianowski Kamil Dziubek David Avnir

In situ crystallization of liquids is usually connotated with the crystallization by lowering temperature, which started to be routinely applied in the 1950's [e.g. 1-4], and was perfected in the 1980's [5,6]. In situ temperature crystallization is routinely applied in neutron diffraction. In fact the low-temperature diffraction studies are regarded as the most accurate structural data. At the ...

Journal: :Acta crystallographica. Section D, Biological crystallography 2005
Wei Gao Shu Xing Li Ru Chang Bi

Macromolecular crystallization remains a bottleneck in structure determination by X-ray diffraction. Based on the data reflecting success rates of crystallization conditions in different screens and the information derived from the BMCD and other related studies, a simplified screen has been designed to increase the success rate of traditional screening and to save samples, time and cost. The s...

Journal: :international journal of nano dimension 0
a. khanfekr department of metallurgical and materials engineering, iran university of science and technology (iust), narmak, tehran, iran. m. tamizifar department of metallurgical and materials engineering, iran university of science and technology (iust), narmak, tehran, iran. r. naghizadeh department of metallurgical and materials engineering, iran university of science and technology (iust), narmak, tehran, iran.

nano-sized batio3 powders with particular nb concentrations were prepared by rotary- hydrothermal (rh) method. hydrothermal method was used at 180 °c for 5 hours with new ti pressure and the teflon vessel was rotated at a speed of 160 rpm during the hydrothermal reaction. new hydrothermal method was used instead of previous solid state reaction for the system batio3±nb2o3 in high temperature to...

Abdolrauf Samadi-Maybodi Mohammad Fatemi, Neda Asemi Seyed Azizi,

Perlite or pearl stone is a natural glass which has formed by rapid cooling of viscous lava or magma. Perlite is mainly composed of silica, aluminum, potassium and sodium. In this experiment, perlite was used as a low-cost source of Si and Al to synthesis of sodalite zeolite using the alkaline hydrothermal treatment. A statistical Taguchi design of experiments was employed to evaluate the effec...

Journal: :Acta crystallographica. Section D, Biological crystallography 2008
Giovanna Tosi Simona Fermani Giuseppe Falini José Antonio Gavira Gallardo Juan Manuel García Ruiz

Functionalized mica sheets and polystyrene films exposing ionisable groups have been used as heterogeneous nucleating surfaces for model proteins. Surfaces with different densities of amino or sulfonated groups have been prepared. Crystallization trials were carried out using the hanging-drop vapour-diffusion method. The results show that using these surfaces the starting protein concentration ...

2015
Laura Y. Pfund Christopher P. Price Jessica J. Frick Adam J. Matzger

To investigate the hypothesis that molecules acting as crystallization inhibitors in solution could be transformed into crystallization promoters, additives were synthesized that mimic the pharmaceuticals acetaminophen and mefenamic acid and also possess polymerizable functionality. It was found that, in solution, these additives face-selectively inhibit crystal growth and lead to overall slowe...

2001
C. C. Hays W. L. Johnson T. J. Rathz M. B. Robinson

The crystallization kinetics of Zr58.5Nb2.8Cu15.6Ni12.8Al10.3 were studied in an electrostatic levitation ~ESL! apparatus. The measured critical cooling rate is 1.75 K/s. Zr58.5Nb2.8Cu15.6Ni12.8Al10.3 is the first bulk-metallic-glass-forming liquid that does not contain beryllium to be vitrified by purely radiative cooling in the ESL. Furthermore, the sluggish crystallization kinetics enable th...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید