scholarly journals Theoretical and Experimental Study of New Photochromic Bis-Spiropyrans with Hydroxyethyl and Carboxyethyl Substituents

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
E. L. Mukhanov ◽  
I. V. Dorogan ◽  
A. V. Chernyshev ◽  
S. O. Bezuglyi ◽  
I. V. Ozhogin ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Experimental Study ◽  
Metal Ions ◽  
Theoretical Modeling ◽  
Thermal Decay ◽  
Improved Stability ◽  
Thermal Stability Of

Two new asymmetrical bis-spiropyrans with nonequivalent spiropyran units have been investigated. Hydroxyethyl and carboxyethyl substituents have been used to improve thermal stability of the photoinduced merocyanine forms of the bis-spiropyrans. 2-Hydroxyethyl substituted compound is characterized by 4 times more stable merocyanine isomer. 2-Carboxyethyl substituent in the hetarene part enables chelation by metal ions and controllably stabilizes the merocyanine from thermal decay. As a result of theoretical modeling and photochemical experiments, it was shown that obtained compounds are perspective prototypes for multistate light-driven switches with improved stability of photoinduced forms.

Theoretical analysis and experimental study on thermal stability of high-speed motorized spindle

2017 ◽  
Vol 69 (6) ◽  
pp. 1049-1065 ◽  
Author(s):  
Zhe Liu ◽  
Wei Chen ◽  
Desheng Li ◽  
Wenjing Zhang
Keyword(s):  
Thermal Stability ◽  
Experimental Study ◽  
Theoretical Analysis ◽  
High Speed ◽  
Thermal Deformation ◽  
Motorized Spindle ◽  
Content Type ◽  
Front End ◽  
Temperature Distributions ◽  
Thermal Stability Of

Purpose In high-speed processing, the influence on the machining accuracy of a machine tool is greatly caused by the thermal deformation of the motorized spindle; a further study on the thermal characteristics of the spindle is given in this paper. This study aims to reduce the thermal error and improve the performance of the machine tool by discussing the relationships between the temperature distributions and rotating accuracy caused by the thermal deformations of the spindle. Design/methodology/approach The paper opted for a method combining the theoretical analysis and the experimental study to study the thermal stability of the high-speed motorized spindle. First of all, a finite element model of the spindle was built with ANSYS, whereby temperature distributions and the thermal deformations were successively obtained at different speeds. And then, both the temperature field and the rotating accuracy of the motorized spindle were measured simultaneously by the thermal stability experiment. Finally, the experimental and theoretical results were compared and validated. Findings The thermal stability of the motorized spindle was studied in this paper, and some findings from the study were as follows: the spindle’s rotating accuracy maintained good in X direction but bad in Y and Z directions in terms of the deformations; the higher front-end temperature of the spindle which can significantly affect the rotating accuracy is needed to be controlled mainly; the recovery speed of the spindle deformation lagged behind the temperature’s fallback speed; the vibration graph about radial rotating sensitivity synthesized by X1 and X2 presented a trifoliate shape. Originality/value Based on a built test-bed which can synchronously measure the motorized spindle’s temperature distribution and rotating accuracy with five-point method, the coupling effects of the thermal deformation and temperature are embodied, and not only the vibration graph but also the thermal tilt angles can be gained. Therefore, considering the influence of the thermal deformation on the heat generated by the bearings, the paper fulfilled a study by which it was obtained that the front-end temperature of the spindle, which was higher and could significantly affect the rotating accuracy, needed to be controlled mainly.

Thermal stability of dibenzothiophene in closed system pyrolysis: Experimental study and kinetic modelling

2006 ◽  
Vol 37 (1) ◽  
pp. 98-116 ◽  
Author(s):  
C. Dartiguelongue ◽  
F. Behar ◽  
H. Budzinski ◽  
G. Scacchi ◽  
P.M. Marquaire
Keyword(s):  
Thermal Stability ◽  
Experimental Study ◽  
Closed System ◽  
Kinetic Modelling ◽  
Thermal Stability Of

Experimental Study of the Thermal Stability of Austempered Ductile Irons

2002 ◽  
Vol 11 (5) ◽  
pp. 519-526 ◽  
Author(s):  
M.J. Pérez ◽  
M.M. Cisneros ◽  
E. Valdés ◽  
H. Mancha ◽  
H.A. Calderón ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Experimental Study ◽  
Thermal Stability Of

Thermal stability of dithiocarbamates derived from α-amino acids with different metal ions

1993 ◽  
Vol 223 ◽  
pp. 213-221 ◽  
Author(s):  
B. Macías ◽  
J.J. Criado ◽  
M.V. Vaquero ◽  
M.V. Villa
Keyword(s):  
Thermal Stability ◽  
Amino Acids ◽  
Metal Ions ◽  
Thermal Stability Of

An in situ SEM experimental study of the thermal stability of a LAST thermoelectric material

2011 ◽  
Vol 91 (7) ◽  
pp. 443-451 ◽  
Author(s):  
Fei Ren ◽  
Jane Y. Howe ◽  
Larry R. Walker ◽  
Eldon D. Case ◽  
Edgar Lara-Curzio
Keyword(s):  
Thermal Stability ◽  
Experimental Study ◽  
Thermoelectric Material ◽  
Thermal Stability Of
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