scholarly journals Dynamical Properties in Uniform and Periodic Growth Modes of Ascorbic Acid Crystal Domain from Thin Solution Film

2014 ◽  
Vol 83 (6) ◽  
pp. 064002 ◽  
Author(s):  
Yoshihiro Yamazaki ◽  
Mitsunobu Kikuchi ◽  
Akihiko Toda ◽  
Jun-ichi Wakita ◽  
Mitsugu Matsushita
ChemInform ◽  
2001 ◽  
Vol 32 (4) ◽  
pp. no-no
Author(s):  
Janusz Madaj ◽  
Yoko Nishikawa ◽  
V. Prakash Reddy ◽  
Peter Rinaldi ◽  
Tadao Kurata ◽  
...  

2018 ◽  
Vol 3 (1) ◽  
pp. 50-59
Author(s):  
S. Hassan ◽  
F. Adam ◽  
M.R. Abu Bakar

Melting temperature (Tmelt) and enthalpy of fussion (ΔHf ) are important parameters to determine the quality and the thermal stability of active pharmaceutical ingredient (API) crystals. In this study, different habit of ascorbic acid was prepared by using different polar solvents namely water, methanol, ethanol and 2-propanol. Ascorbic acid crystal was then been physically and thermally characterised by using microscopic analysis, thermo gravimetric analysis (TGA) and differential scanning calometry analysis (DSC). This provides an insight into the formation of crystal habit across four different polar protic solvents. The ascorbic acid is found to grow as a cubic or prism crystal when grown in water that provides high hydrogen bond between solvent and solute. As the polarity of the solvents decrease, the hydrogen bond weaken and the width of the crystal become narrower, forming almost a needle like crystal. The thermal stability of ascorbic acid crystal is found to be the most stable when ascorbic acid is crystallized from water (prism) and the weakest from 2-propanol (needle) due to the molecule arrangement in crystal lattice in which resulted from decreasing intermolecular forces in the liquid phase


2009 ◽  
Vol 78 (7) ◽  
pp. 074001 ◽  
Author(s):  
Yoshihiro Yamazaki ◽  
Hiroki Yoshino ◽  
Machiko Izui ◽  
Yukiko Sato ◽  
Mitsugu Matsushita

2000 ◽  
Vol 329 (2) ◽  
pp. 477-485 ◽  
Author(s):  
Janusz Madaj ◽  
Yoko Nishikawa ◽  
V.Prakash Reddy ◽  
Peter Rinaldi ◽  
Tadao Kurata ◽  
...  

1999 ◽  
Vol 173 ◽  
pp. 327-338 ◽  
Author(s):  
J.A. Fernández ◽  
T. Gallardo

AbstractThe Oort cloud probably is the source of Halley-type (HT) comets and perhaps of some Jupiter-family (JF) comets. The process of capture of Oort cloud comets into HT comets by planetary perturbations and its efficiency are very important problems in comet ary dynamics. A small fraction of comets coming from the Oort cloud − of about 10−2− are found to become HT comets (orbital periods < 200 yr). The steady-state population of HT comets is a complex function of the influx rate of new comets, the probability of capture and their physical lifetimes. From the discovery rate of active HT comets, their total population can be estimated to be of a few hundreds for perihelion distancesq <2 AU. Randomly-oriented LP comets captured into short-period orbits (orbital periods < 20 yr) show dynamical properties that do not match the observed properties of JF comets, in particular the distribution of their orbital inclinations, so Oort cloud comets can be ruled out as a suitable source for most JF comets. The scope of this presentation is to review the capture process of new comets into HT and short-period orbits, including the possibility that some of them may become sungrazers during their dynamical evolution.


1951 ◽  
Vol 18 (2) ◽  
pp. 224-229 ◽  
Author(s):  
Joseph T. Freeman ◽  
Roberta Hafkesbring

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