Molecular Orientation and Absorbance Determination for Oriented Polymers by Tilting Method with Nonpolarized Infrared Light

1971 ◽  
Vol 25 (3) ◽  
pp. 355-360 ◽  
Author(s):  
J. L. Koenig ◽  
M. Itoga
Keyword(s):  
Molecular Orientation ◽  
New Method ◽  
Infrared Light ◽  
Oriented Polymers ◽  
Oriented Polymer ◽  
Polymer Systems ◽  
Unpolarized Light ◽  
Extrapolation Technique ◽  
Experimental Errors

A new method of measuring the absorbance corrected for orientation and the orientation of oriented polymer systems is derived. The method using unpolarized light utilizes a linear plotting and extrapolation technique to minimize experimental errors. The method is applied to oriented nlyon 66 samples and the results are compared with the previous methods.

scholarly journals Accurate Model-Based Point of Gaze Estimation on Mobile Devices

Vision ◽  
2018 ◽  
Vol 2 (3) ◽  
pp. 35 ◽  
Author(s):  
Braiden Brousseau ◽  
Jonathan Rose ◽  
Moshe Eizenman
Keyword(s):  
Eye Tracking ◽  
Mobile Devices ◽  
Head Movements ◽  
Roll Angle ◽  
New Method ◽  
Estimation Methods ◽  
Infrared Light ◽  
Gaze Estimation ◽  
Tracking Systems ◽  
Estimation Models

The most accurate remote Point of Gaze (PoG) estimation methods that allow free head movements use infrared light sources and cameras together with gaze estimation models. Current gaze estimation models were developed for desktop eye-tracking systems and assume that the relative roll between the system and the subjects’ eyes (the ’R-Roll’) is roughly constant during use. This assumption is not true for hand-held mobile-device-based eye-tracking systems. We present an analysis that shows the accuracy of estimating the PoG on screens of hand-held mobile devices depends on the magnitude of the R-Roll angle and the angular offset between the visual and optical axes of the individual viewer. We also describe a new method to determine the PoG which compensates for the effects of R-Roll on the accuracy of the POG. Experimental results on a prototype infrared smartphone show that for an R-Roll angle of 90 ° , the new method achieves accuracy of approximately 1 ° , while a gaze estimation method that assumes that the R-Roll angle remains constant achieves an accuracy of 3.5 ° . The manner in which the experimental PoG estimation errors increase with the increase in the R-Roll angle was consistent with the analysis. The method presented in this paper can improve significantly the performance of eye-tracking systems on hand-held mobile-devices.

Scattering Studies of Cyrstallization in Highly Oriented Polymers

1986 ◽  
Vol 79 ◽  
Author(s):  
J. M. Schultz
Keyword(s):  
Molecular Weight ◽  
Glass Formation ◽  
Molecular Orientation ◽  
Local Strain ◽  
Temperature Fields ◽  
Low Molecular Weight ◽  
Molten State ◽  
Molecular Configuration ◽  
Oriented Polymers ◽  
Coiled State

The solidification of low molecular weight materials from their melts (in the absence of temperature fields) generally leads to a product with no preferred orientation, independent of the extent or rate of deformation of the melt. The solidification of polymers from a highly deformed melt or solution nearly always leads to a product with preferred molecular orientation. Further, the rate of solidification can be significantly increased by melt deformation. The change in rate, relative to that in a quiescent melt or solution, can be several orders of magnitude [1]. These differences, relative to small-molecule systems, arise from the degree to which orientation and local strain can be maintained in the melt. Due to the long-range connectivity within a polymer molecule, it is possible to impart large extensions to these molecules in the molten state, and significant time is often required for the molecules to relax back to their undistorted, coiled state. If crystallization or glass formation occurs before the chain can relax, an extended molecular configuration can be retained. Thus in the solidification of oriented polymers there exists a competition between the “freezing” of the molecular orientation and the relaxation (re-coiling) of the molecules.

scholarly journals Explaining the entropy concept and entropy components

2017 ◽  
Author(s):  
Marko Popovic
Keyword(s):  
Molecular Orientation ◽  
Classical Method ◽  
Energy State ◽  
Thermodynamic System ◽  
Absolute Zero ◽  
New Method ◽  
Residual Entropy ◽  
Total Entropy ◽  
Point Energy ◽  
Thermal Entropy

Total entropy of a thermodynamic system consists of two components: thermal entropy due to energy, and residual entropy due to molecular orientation. In this article, a three-step method for explaining entropy is suggested. Step one is to use a classical method to introduce thermal entropy <i>S<sub>TM</sub></i> as a function of temperature <i>T</i> and heat capacity at constant pressure <i>C<sub>p</sub></i>: <i>S<sub>TM</sub></i> = <i>∫(C<sub>p</sub>/T) dT</i>. Thermal entropy is the entropy due to uncertainty in motion of molecules and vanishes at absolute zero (zero-point energy state). It is also the measure of useless thermal energy that cannot be converted into useful work. The next step is to introduce residual entropy <i>S<sub>0</sub></i> as a function of the number of molecules <i>N</i> and the number of distinct orientations available to them in a crystal <i>m</i>: <i>S<sub>0</sub> = N k<sub>B</sub> ln m</i>, where <i>k<sub>B</sub></i> is the Boltzmann constant. Residual entropy quantifies the uncertainty in molecular orientation. Residual entropy, unlike thermal entropy, is independent of temperature and remains present at absolute zero. The third step is to show that thermal entropy and residual entropy add up to the total entropy of a thermodynamic system <i>S</i>: <i>S = S<sub>0</sub> + S<sub>TM</sub></i>. This method of explanation should result in a better comprehension of residual entropy and thermal entropy, as well as of their similarities and differences. The new method was tested in teaching at Faculty of Chemistry University of Belgrade, Serbia. The results of the test show that the new method has a potential to improve the quality of teaching.

Molecular engineering of liquid-crystalline polymers: architecture and functionalization

1990 ◽  
Vol 330 (1610) ◽  
pp. 95-108 ◽  
Keyword(s):  
Liquid Crystalline ◽  
Liquid Crystalline Polymers ◽  
Amorphous Polymers ◽  
Molecular Engineering ◽  
Molecular Architecture ◽  
Oriented Polymer ◽  
Polymer Backbone ◽  
Polymer Systems ◽  
Crystalline Polymers ◽  
The Past

In the past few years molecular engineering of liquid-crystalline (LC) polymers with respect to molecular architecture and functionalization has become increasingly important. Molecular architecture of LC polymers, i.e. the variation of the arrangement of mesogens, the variation of their shapes (rod, disc, board) and the variation of the polymer backbone, leads to polymers with new LC phases and new properties. Functionalized or dye-containing polymers can be used for a destruction or even the formation of the LC phase by photoreactions as well as for photochromic effects. The induction of discotic phases in amorphous polymers with disc-like mesogens is possible by charge-transfer interactions and opens the accessibility for a wide variety of highly oriented polymer systems.

Laser-Induced Shape Memory Polymer Actuator Used in a Deployable Display

2013 ◽  
Vol 333-335 ◽  
pp. 1926-1929 ◽  
Author(s):  
Da Wei Zhang ◽  
Jia Jia Zhang ◽  
Rui Wei ◽  
Jing Wen Xia ◽  
Dan Ni Jiao ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Shape Memory ◽  
Shape Memory Polymer ◽  
Electronic Equipment ◽  
New Method ◽  
Infrared Light ◽  
Back Side ◽  
Flexible Display ◽  
Flexible Displays ◽  
Polymer Actuator

Deployable flexible displays attract a great attention recently. The flexible display used on electronic equipment have been developed, which can deploy to reveal a much larger screen or rolled up. However, one of major problems is its actuation of deployment and fixture. In this paper, a deployable display actuated by the SMP actuator is proposed. The shape memory polymer (SMP) actuator, which is considered to be attached to the back side of a flexible display, is used to deploy and fix the flexible display. A new method of laser-induced actuation of SMP actuator is investigated. By this method, the SMP can be induced by infrared light transmitted through a treated optical fiber embedded in the actuator.

scholarly journals Explaining the entropy concept and entropy components

2017 ◽  
Author(s):  
Marko Popovic
Keyword(s):  
Molecular Orientation ◽  
Classical Method ◽  
Energy State ◽  
Thermodynamic System ◽  
Absolute Zero ◽  
New Method ◽  
Residual Entropy ◽  
Total Entropy ◽  
Point Energy ◽  
Thermal Entropy

Total entropy of a thermodynamic system consists of two components: thermal entropy due to energy, and residual entropy due to molecular orientation. In this article, a three-step method for explaining entropy is suggested. Step one is to use a classical method to introduce thermal entropy <i>S<sub>TM</sub></i> as a function of temperature <i>T</i> and heat capacity at constant pressure <i>C<sub>p</sub></i>: <i>S<sub>TM</sub></i> = <i>∫(C<sub>p</sub>/T) dT</i>. Thermal entropy is the entropy due to uncertainty in motion of molecules and vanishes at absolute zero (zero-point energy state). It is also the measure of useless thermal energy that cannot be converted into useful work. The next step is to introduce residual entropy <i>S<sub>0</sub></i> as a function of the number of molecules <i>N</i> and the number of distinct orientations available to them in a crystal <i>m</i>: <i>S<sub>0</sub> = N k<sub>B</sub> ln m</i>, where <i>k<sub>B</sub></i> is the Boltzmann constant. Residual entropy quantifies the uncertainty in molecular orientation. Residual entropy, unlike thermal entropy, is independent of temperature and remains present at absolute zero. The third step is to show that thermal entropy and residual entropy add up to the total entropy of a thermodynamic system <i>S</i>: <i>S = S<sub>0</sub> + S<sub>TM</sub></i>. This method of explanation should result in a better comprehension of residual entropy and thermal entropy, as well as of their similarities and differences. The new method was tested in teaching at Faculty of Chemistry University of Belgrade, Serbia. The results of the test show that the new method has a potential to improve the quality of teaching.

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