Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3

recrystallization Related Publications

3 Determination of Recrystallization Temperature of Varying Degrees Formed Aluminium, by DMTA Technique

Authors: Zoltan Weltsch, Zsolt Dugár, Péter Barkóczy, Gábor Béres, Dávid Kis, Attila Bata, Tamás Dugár

Abstract:

This study is about the structural transformations of aluminium examining with the Dynamic Mechanical Thermal Analyzer (DMTA). It is a faster and simpler measuring method to make consequence about the metal’s structural transformations. The device measures the changing of the mechanical characteristics depending on the heating rate, and concludes certain transformations. This measuring method fast and shows clean-cut results comparing the conventional ways. Applying polymer measuring devices for metal investigations is not widespread method. One of the adaptable ways is shown in this study. The article compares the results of the small specimen test and the DMTA method, considering the temperature and the forming dependence of recrystallization temperature.

Keywords: Rotation, Cold Forming, recrystallization, DMTA

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2 Evaluation and Preparation of Crystal Modifications of Artesunate: In vivo Studies

Authors: S. Gupta, R. Chadha

Abstract:

Five crystal modifications of water insoluble artesunate were generated by recrystallizing it from various solvents with improved physicochemical properties. These generated crystal forms were characterized to select the most potent and soluble form. SEM of all the forms showed changes in external shape leading them to be different morphologically. DSC thermograms of Form III and Form V showed broad endotherm peaks at 83.04oC and 76.96oC prior to melting fusion of drug respectively. Calculated weight loss in TGA revealed that Form III and Form V are methanol and acetone solvates respectively. However, few additional peaks were appeared in XRPD pattern in these two solvate forms. All forms exhibit exothermic behavior in buffer and two solvates display maximum ease of molecular release from the lattice. Methanol and acetone solvates were found to be most soluble forms and exhibited higher antimalarial efficacy showing higher survival rate (83.3%) after 30 days.

Keywords: recrystallization, artesunate, Crystal modifications, in vivo studies

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1 Effect of CW Laser Annealing on Silicon Surface for Application of Power Device

Authors: Kensuke Akiyama, Satoru Kaneko, Takeshi Ozawa, Takeshi Ito, Manabu Yasui, Chihiro Kato, Satomi Tanaka, Yasuo Hirabayashi, Akira Matsuno, Takashi Nire, Hiroshi Funakubo, Mamoru Yoshimoto

Abstract:

As application of re-activation of backside on power device Insulated Gate Bipolar Transistor (IGBT), laser annealing was employed to irradiate amorphous silicon substrate, and resistivities were measured using four point probe measurement. For annealing the amorphous silicon two lasers were used at wavelength of visible green (532 nm) together with Infrared (793 nm). While the green laser efficiently increased temperature at top surface the Infrared laser reached more deep inside and was effective for melting the top surface. A finite element method was employed to evaluate time dependent thermal distribution in silicon substrate.

Keywords: laser, Absorption, Finite Element Method, Silicon, recrystallization, resistivity, annealing, melting point, thermal distribution, latent heat of fusion

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