Addition polymerization in a nematic medium: Effects of an anisotropic solvent in a kinetic gelation model

1995 ◽  
Vol 52 (4) ◽  
pp. 4549-4552 ◽  
Author(s):  
Wei-Jou Chen ◽  
Shu-Hsia Chen
Keyword(s):  
Medium Effects ◽  
Addition Polymerization

Gender Differences in the Mental Rotations Test (MRT) Are Not Due to Task Complexity

2008 ◽  
Vol 29 (3) ◽  
pp. 130-133 ◽  
Author(s):  
Corinna Titze ◽  
Martin Heil ◽  
Petra Jansen
Keyword(s):  
Gender Differences ◽  
Mental Rotation ◽  
Task Complexity ◽  
Time Constraints ◽  
Medium Effects ◽  
Performance Factors ◽  
Mental Rotations ◽  
Sufficient Power ◽  
Forced Choice Tasks ◽  
Choice Tasks

Gender differences are one of the main topics in mental rotation research. This paper focuses on the influence of the performance factor task complexity by using two versions of the Mental Rotations Test (MRT). Some 300 participants completed the test without time constraints, either in the regular version or with a complexity reducing template creating successive two-alternative forced-choice tasks. Results showed that the complexity manipulation did not affect the gender differences at all. These results were supported by a sufficient power to detect medium effects. Although performance factors seem to play a role in solving mental rotation problems, we conclude that the variation of task complexity as realized in the present study did not.

Microscopic medium effects on a chemical reaction. A theoretical study of decarboxylation catalyzed by cyclodextrins as an enzyme model

1993 ◽  
Vol 115 (7) ◽  
pp. 2903-2911 ◽  
Author(s):  
Takao Furuki ◽  
Fumio Hosokawa ◽  
Minoru Sakurai ◽  
Yoshio Inoue ◽  
Riichiro Chujo
Keyword(s):  
Chemical Reaction ◽  
Theoretical Study ◽  
Medium Effects ◽  
Enzyme Model

Sonochemical Synthesis of Poly (Methyl Acrylate)

2008 ◽  
Vol 136 ◽  
pp. 175-190 ◽  
Author(s):  
M.A. Jothi Rajan ◽  
T. Mathavan ◽  
T.S. Vivekanandam ◽  
S. Umapathy ◽  
V. Ganesan ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Methyl Acrylate ◽  
Radical Addition ◽  
Thermal Method ◽  
Sonochemical Synthesis ◽  
Aqueous Sodium ◽  
Addition Polymerization ◽  
Clean Environment ◽  
Free Radical Addition ◽  
Thermal Stability Of

Polymers are prepared by various methods. The method of preparation plays an important role in deciding many of the physical properties of polymers. In this work Poly (Methyl Acrylate), PMA, is synthesized by free radical addition polymerization in the presence a monomer, an initiator under the influence of ultrasound. Methyl Acrylate (E-Merck, India) of proper strength is mixed with aqueous sodium peroxodisulphate solution of known strength and the time of passage of ultrasound is varied in steps of 30 minutes and 10 samples of solid PMA are obtained for 10 different periods of passage of ultrasound. Solid PMA samples are purified and air-dried under clean environment. TGA, DTA measurements are done on all the 10 PMA samples. The thermal stability of PMA with the change in the time of passage of ultrasound is discussed quantitatively. The thermal stability of PMA, synthesized sonochemically shows better results over the thermal method of synthesis. However in this paper we report the measurements made on PMA samples synthesized at 30 and 300 minutes sonication periods respectively.

scholarly journals Metathesis and addition polymerization of novel Me3Si- and Me3Ge-substituted tricyclononenes

2012 ◽  
Vol 45 (7) ◽  
pp. 718-726 ◽  
Author(s):  
Maxim Bermeshev ◽  
Boris Bulgakov ◽  
Dmitry Demchuk ◽  
Marina Filatova ◽  
Lyudmila Starannikova ◽  
...  
Keyword(s):  
Addition Polymerization
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