0416 Mechanism of molecule orientation on application process of chromonic liquid crystal in Meniscus region

2012 ◽  
Vol 2012.49 (0) ◽  
pp. 041601-041602
Author(s):  
Yuzo AMAGASA ◽  
Tsutomu TAKAHASHI
Author(s):  
K.J. Ihn ◽  
R. Pindak ◽  
J. A. N. Zasadzinski

A new liquid crystal (called the smectic-A* phase) that combines cholesteric twist and smectic layering was a surprise as smectic phases preclude twist distortions. However, the twist grain boundary (TGB) model of Renn and Lubensky predicted a defect-mediated smectic phase that incorporates cholesteric twist by a lattice of screw dislocations. The TGB model for the liquid crystal analog of the Abrikosov phase of superconductors consists of regularly spaced grain boundaries of screw dislocations, parallel to each other within the grain boundary, but rotated by a fixed angle with respect to adjacent grain boundaries. The dislocations divide the layers into blocks which rotate by a discrete amount, Δθ, given by the ratio of the layer spacing, d, to the distance between grain boundaries, lb; Δθ ≈ d/lb (Fig. 1).


Author(s):  
B.D. Terris ◽  
R. J. Twieg ◽  
C. Nguyen ◽  
G. Sigaud ◽  
H. T. Nguyen

We have used a force microscope in the attractive, or noncontact, mode to image a variety of surfaces. In this mode, the microscope tip is oscillated near its resonant frequency and shifts in this frequency due to changes in the surface-tip force gradient are detected. We have used this technique in a variety of applications to polymers, including electrostatic charging, phase separation of ionomer surfaces, and crazing of glassy films.Most recently, we have applied the force microscope to imaging the free surfaces of chiral liquid crystal films. The compounds used (Table 1) have been chosen for their polymorphic variety of fluid mesophases, all of which exist within the temperature control range of our force microscope.


2020 ◽  
Vol 5 (1) ◽  
pp. 192-205
Author(s):  
Lesley Sylvan ◽  
Andrea Perkins ◽  
Carly Truglio

Purpose The purpose of this study is to better understand the experiences faced by students during the application process for master's degree programs in speech-language pathology. Method Data were collected through administering an online survey to 365 volunteers who had applied to master's degree programs in speech-language pathology. Survey questions were designed to gain the student perspective of the application process through exploration of students' deciding factors for top choices of graduate programs, emotional involvement in the application process, biases/rumors heard, student challenges, advice to future applicants, and what students would change about the application process. Results Factors that influenced participants' reasoning for selecting their “top choice” programs were largely consistent with previous studies. Issues that shaped the student experience applying to graduate school for speech-language pathology included financial constraints, concern regarding the prominence of metrics such as Graduate Record Examinations scores in the admissions process, a perceived lack of guidance and advising from faculty, and confusion regarding variation among graduate program requirements. Conclusion Gaining insight into the student experience with the application process for graduate programs in speech-language pathology yields useful information from a perspective not frequently explored in prior literature. While the data presented in this study suggest the process is confusing and challenging to many applicants, the discussion highlights practical solutions and sheds light on key issues that should be considered carefully by individual graduate programs as well as the field as a whole.


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