scholarly journals From Bend to Splay Dominated Elasticity in Nematics

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 831
Author(s):  
Davide Revignas ◽  
Alberta Ferrarini
Keyword(s):  
Liquid Crystal ◽  
Nematic Phase ◽  
Low Cost ◽  
Elastic Behavior ◽  
Computational Investigation ◽  
Apical Angle ◽  
Polar Order ◽  
The Past ◽  
Bend Angles ◽  
Analogous Effect

In the past decade, much evidence has been provided for an unusually low cost for bend deformations in the nematic phase of bent-core mesogens and bimesogens (liquid crystal dimers) having a bent shape on average. Recently, an analogous effect was observed for the splay mode of bent-core mesogens with an acute apical angle. Here, we present a systematic computational investigation of the Frank elastic constants of nematics made of V-shaped particles, with bend angles ranging from acute to obtuse. We show that by tuning this angle, the elastic behavior switches from bend dominated (K33>K11) to splay dominated (K11>K33), with anomalously low values of the splay and the bend constant, respectively. This is related to a change in the shape polarity of particles, which is associated with the emergence of polar order, longitudinal for splay and transversal for bend deformations. Crucial to this study is the use of a recently developed microscopic elastic theory, able to account for the interplay of mesogen morphology and director deformations.

Development of polar order in a bent-core liquid crystal with a new sequence of two orthogonal smectic and an adjacent nematic phase

2011 ◽  
Vol 21 (46) ◽  
pp. 18711 ◽  
Author(s):  
Govindaswamy Shanker ◽  
Marko Prehm ◽  
Mamatha Nagaraj ◽  
Jagdish K. Vij ◽  
Carsten Tschierske
Keyword(s):  
Liquid Crystal ◽  
Nematic Phase ◽  
Polar Order

Cross-culture outcomes of a brazilian professor Fulbright in the USA

2017 ◽  
Vol 26 (50) ◽  
pp. 115
Author(s):  
Marcelo Da Silva Leite ◽  
Celeste Gaia
Keyword(s):  
Higher Education ◽  
Low Cost ◽  
Cross Culture ◽  
College And University ◽  
Governmental Agencies ◽  
The Past ◽  
University Curriculum ◽  
Fulbright Scholar ◽  
The Usa ◽  
Higher Education Costs

Over the past decade due the expansion of globalization there has been an increasing emphasis on internationalization among faculty, administration and accrediting agencies in the Higher Education.  Although to promote internationalization in the Higher Education, costs are a big challenge, one way to have the international actions with low cost, it is seeking for grants from different governmental agencies and foundations.The Fulbright Scholar program provides a long-standing and externally-funded means for internationalizing college and university curriculum. This article is going to share the perspective   of a Brazilian Fulbright Scholar at an American college and the institution perspective of the Fulbright scholar participation at the College.

Liquid Crystal Trimers Incorporating Saturated Isosteres of Benzene and Exhibiting Modulated Nematic Phases

2019 ◽  
Author(s):  
Adam Al-Janabi ◽  
Richard Mandle
Keyword(s):  
Liquid Crystal ◽  
Helical Structure ◽  
Molecular Shape ◽  
Saturated Hydrocarbons ◽  
Fluid System ◽  
Structural Requirement ◽  
Disubstituted Benzene ◽  
Bona Fide ◽  
Nematic Phases ◽  
Bend Angles

<p>The nematic twist-bend (N<sub>TB</sub>) liquid crystal phase possesses a local helical structure with a pitch length of a few nanometres and is the first example of spontaneous symmetry breaking in a fluid system. All known examples of the N­<sub>TB­</sub> phase occur in materials whose constituent mesogenic units are aromatic hydrocarbons. It is not clear if this is due to synthetic convenience or a <i>bona fide</i> structural requirement for a material to exhibit this phase of matter. In this work we demonstrate that materials consisting largely of saturated hydrocarbons could also give rise to this mesophase. Furthermore, replacement of 1,4-disubstituted benzene with <i>trans</i> 1,4-cyclohexane or even 1,4-cubane does not especially alter the transition temperatures of the resulting material nor does it appear to impact upon the heliconical tilt angle, suggesting the local structure of the phase is unperturbed. Calculating the probability distribution of bend angles reveals that the choice of isosteric group has little impact on the overall molecular shape, demonstrating the shape-driven nature of the N<sub>TB</sub> phase. </p>

Reversible microscale assembly of nanoparticles driven by the phase transition of a thermotropic liquid crystal

2017 ◽  
Author(s):  
Niamh Mac Fhionnlaoich ◽  
Stephen Schrettl ◽  
Nicholas B. Tito ◽  
Ye Yang ◽  
Malavika Nair ◽  
...  
Keyword(s):  
Phase Transition ◽  
Liquid Crystal ◽  
Self Assembly ◽  
Nematic Phase ◽  
Hierarchical Control ◽  
Building Blocks ◽  
Model System ◽  
Microscopic Level ◽  
Reversible Process ◽  
Thermotropic Liquid Crystal

The arrangement of nanoscale building blocks into patterns with microscale periodicity is challenging to achieve via self-assembly processes. Here, we report on the phase transition-driven collective assembly of gold nanoparticles in a thermotropic liquid crystal. A temperature-induced transition from the isotropic to the nematic phase leads to the assembly of individual nanometre-sized particles into arrays of micrometre-sized aggregates, whose size and characteristic spacing can be tuned by varying the cooling rate. This fully reversible process offers hierarchical control over structural order on the molecular, nanoscopic, and microscopic level and is an interesting model system for the programmable patterning of nanocomposites with access to micrometre-sized periodicities.

An Assessment of a Low-Cost Wastewater Disposal System after Twenty-Five Years of Operation

1987 ◽  
Vol 19 (5-6) ◽  
pp. 701-710 ◽  
Author(s):  
B. L. Reidy ◽  
G. W. Samson
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Wastewater Disposal ◽  
Industrial Base ◽  
Industrial Wastewaters ◽  
The Past ◽  
Gasification Process ◽  
Appropriate Treatment ◽  
Environmentally Safe ◽  
Coal Resource

A low-cost wastewater disposal system was commissioned in 1959 to treat domestic and industrial wastewaters generated in the Latrobe River valley in the province of Gippsland, within the State of Victoria, Australia (Figure 1). The Latrobe Valley is the centre for large-scale generation of electricity and for the production of pulp and paper. In addition other industries have utilized the brown coal resource of the region e.g. gasification process and char production. Consequently, industrial wastewaters have been dominant in the disposal system for the past twenty-five years. The mixed industrial-domestic wastewaters were to be transported some eighty kilometres to be treated and disposed of by irrigation to land. Several important lessons have been learnt during twenty-five years of operating this system. Firstly the composition of the mixed waste stream has varied significantly with the passage of time and the development of the industrial base in the Valley, so that what was appropriate treatment in 1959 is not necessarily acceptable in 1985. Secondly the magnitude of adverse environmental impacts engendered by this low-cost disposal procedure was not imagined when the proposal was implemented. As a consequence, clean-up procedures which could remedy the adverse effects of twenty-five years of impact are likely to be costly. The question then may be asked - when the total costs including rehabilitation are considered, is there really a low-cost solution for environmentally safe disposal of complex wastewater streams?

Dielectric Relaxation in Liquid Crystal Phases with Polar Order

2003 ◽  
Vol 297 (1) ◽  
pp. 91-105
Author(s):  
B. Żywucki ◽  
W. Kuczyński ◽  
J. Małecki
Keyword(s):  
Liquid Crystal ◽  
Dielectric Relaxation ◽  
Polar Order ◽  
Crystal Phases ◽  
Liquid Crystal Phases

Economic Consequences of War

1943 ◽  
Vol 3 (S1) ◽  
pp. 1-8
Author(s):  
Curtis P. Nettels
Keyword(s):  
Low Cost ◽  
Economic Consequences ◽  
Competitive Advantages ◽  
Competitive Position ◽  
The Past ◽  
History Of ◽  
Costs Of Production ◽  
Foreign Competitors

One influence of war has repeatedly asserted itself in the past—an effect on the costs of production and on the competitive position of the industries and firms of victorious or neutral nations. This subject needs more study, but certain facts suggest a hypothesis, of three parts. First: war expands some industries or concerns, increases their efficiency, enables them to operate, at the end of the struggle, on a comparatively low-cost basis, intensifies their competitive advantages, and improves their position in relation to foreign competitors. Second: war—for the duration—bolsters up some high-cost units by enabling them to sell at a profit all they can produce. The end of the war places such high-cost units at a disadvantage in the process of absorbing the shocks of the transition to a peacetime economy. Third: the history of postwar periods usually exhibits a sharp contest between such low-cost and high-cost enterprises. While “low cost” and “high cost” may refer to the relative positions of units within the same country, in most of this discussion, the terms will be applied to the producers of one country (either victor or neutral) to mean that their costs are low or high in comparison with those of their foreign competitors.

scholarly journals Normative Aspects of Nudging in the International Sphere

AJIL Unbound ◽  
2021 ◽  
Vol 115 ◽  
pp. 263-267
Author(s):  
Doron Teichman ◽  
Eyal Zamir
Keyword(s):  
Energy Consumption ◽  
Organ Donation ◽  
Low Cost ◽  
National Level ◽  
The Past ◽  
The People ◽  
Posthumous Organ Donation ◽  
Regulatory Problems

The use of nudges—“low-cost, choice-preserving, behaviorally informed approaches to regulatory problems”—has become quite popular at the national level in the past decade or so. Examples include changing the default concerning employees’ saving for retirement in a bid to encourage such saving; altering the default about consent to posthumous organ donation to increase the supply of organs for transplantation; and informing people about other people's energy consumption to spur them to reduce theirs. Nudges are therefore used to promote the welfare of the people being nudged, and of society at large. However, the use of nudges has sparked a lively normative debate. When turning to the international arena, new arguments for and against nudges can be raised. This essay focuses on the normative aspects of using nudges in the international arena.

Fused Ambipolar Aza-isoindigos with NIR absorption

2021 ◽  
Author(s):  
Liping Yao ◽  
Danlei Zhu ◽  
Hailiang Liao ◽  
Sheik Haseena ◽  
Mahesh kumar Ravva ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
High Performance ◽  
Low Cost ◽  
Light Weight ◽  
The Past ◽  
Pi Conjugated ◽  
Nir Absorption ◽  
Conjugated Organic Semiconductors

Due to their advantages of low-cost, light-weight, and mechanical flexibility, much attention has been focused on pi-conjugated organic semiconductors. In the past decade, although many materials with high performance has...

scholarly journals SpheroidPicker for automated 3D cell culture manipulation using deep learning

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Istvan Grexa ◽  
Akos Diosdi ◽  
Maria Harmati ◽  
Andras Kriston ◽  
Nikita Moshkov ◽  
...  
Keyword(s):  
Cell Culture ◽  
Precision Medicine ◽  
High Throughput Screening ◽  
Standard Sample ◽  
Ex Vivo ◽  
Low Cost ◽  
3D Cell Culture ◽  
Syringe Pump ◽  
Experimental Conditions ◽  
The Past

AbstractRecent statistics report that more than 3.7 million new cases of cancer occur in Europe yearly, and the disease accounts for approximately 20% of all deaths. High-throughput screening of cancer cell cultures has dominated the search for novel, effective anticancer therapies in the past decades. Recently, functional assays with patient-derived ex vivo 3D cell culture have gained importance for drug discovery and precision medicine. We recently evaluated the major advancements and needs for the 3D cell culture screening, and concluded that strictly standardized and robust sample preparation is the most desired development. Here we propose an artificial intelligence-guided low-cost 3D cell culture delivery system. It consists of a light microscope, a micromanipulator, a syringe pump, and a controller computer. The system performs morphology-based feature analysis on spheroids and can select uniform sized or shaped spheroids to transfer them between various sample holders. It can select the samples from standard sample holders, including Petri dishes and microwell plates, and then transfer them to a variety of holders up to 384 well plates. The device performs reliable semi- and fully automated spheroid transfer. This results in highly controlled experimental conditions and eliminates non-trivial side effects of sample variability that is a key aspect towards next-generation precision medicine.

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