A Self-Oscillating Polymer Chain with High LCST

2014 ◽  
Vol 941-944 ◽  
pp. 1208-1211 ◽  
Author(s):  
Yusuke Hara
Keyword(s):  
Polymer Chain ◽  
Driving Force ◽  
The Self ◽  
Solution Temperature ◽  
The Novel ◽  
Careful Selection ◽  
Critical Solution Temperature ◽  
Sodium Bromate ◽  
Belousov Zhabotinsky Reaction ◽  
Selection Of

A novel self-oscillating polymer displaying a high lower critical solution temperature (LCST) was developed. The novel polymer chain underwent soluble-insoluble self-oscillation induced by a Belousov–Zhabotinsky reaction. The driving force of the self-oscillation was the differing solubility of the polymer chain in the reduced and oxidized states. The amplitude of self-oscillation was hardly affected by the concentration of the oxidant, sodium bromate. In addition, the period of the polymer solution could be controlled by careful selection of the concentration of the sodium bromate.

Self-Oscillating Behaviors of Negatively Charged Polymer Chain Induced by the Belousov-Zhabotinsky Reaction

2011 ◽  
Vol 181-182 ◽  
pp. 206-211
Author(s):  
Yusuke Hara ◽  
Rumana A. Jahan
Keyword(s):  
Polymer Solution ◽  
Polymer Chain ◽  
Control Site ◽  
The Self ◽  
Sodium Bromate ◽  
Bz Reaction ◽  
Free Condition ◽  
Ru Catalyst ◽  
Damping Behavior ◽  
Belousov Zhabotinsky Reaction

In this paper, we studied the effect of the temperature and the initial concentration of sodium bromate (NaBrO3) on the aggregation-disaggregation self-oscillation for a polymer chain. The polymer chain consisted of N-isopropylacrylamide (NIPAAm), Ru catalyst of the BZ reaction and Acrylamide-2-methylpropanesulfonic acid (AMPS) as a solubility control site. The concentration of sodium bromate and the temperature significantly affected the self-oscillating behavior and the period of the aggregation-disaggregation self-oscillation. Moreover, the amplitude of the aggregation-disaggregation self-oscillation of the AMPS-containing polymer solution decreased with time. The damping behavior is originating from the increase in the size of the polymer chain. In addition, this study clarified that the period of the self-oscillation of the AMPS-containing polymer solution in the strongly acidic condition was significantly shorter than that in the acid-free condition.

scholarly journals Dialectal words in the ballad novel “Blakytna Sarna” (“The Blue Chamois”) by M. Nesterchuk. ІІІ

Linguistics ◽  
2020 ◽  
pp. 71-78
Author(s):  
Hryhorii Arkushyn ◽  
Keyword(s):  
Detailed Analysis ◽  
The Novel ◽  
Careful Selection ◽  
Selection Of

In this article, the usage of dialectal words in the ballad novel „Blakytna Sarna” („The Blue Chamois”) by M. Nesterchuk, a native of Volyn oblast, has been analyzed. The detailed analysis of the microtoponyms and anthroponyms proves that fictional tumultuous Zatyshshia village is modern Sylno village (Kivertsi raion, Volyn oblast). In the novel, the vocabulary of the local patois is characterized according to the following plan: dialecticisms that have become the passive vocabulary of the speakers; widely used dialectal words; dialectal synonymy. By comparison with the local patois, it has been identified which dialectal features the writer preferred. It has also been emphasized that the writer accurately explains the meaning of dialecticisms. It has been demonstrated that the writer does not blindly copy the patois, but makes a careful selection of the most common dialectal words.

scholarly journals Self-Healing Hydrogels with both LCST and UCST through Cross-Linking Induced Thermo-Response

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 490 ◽  
Author(s):  
Haifeng Zhao ◽  
Heng An ◽  
Baozhong Xi ◽  
Yan Yang ◽  
Jianglei Qin ◽  
...  
Keyword(s):  
Sol Gel ◽  
Covalent Bond ◽  
The Self ◽  
Solution Temperature ◽  
Cross Linking ◽  
Self Healing ◽  
Critical Solution Temperature ◽  
Upper Critical Solution Temperature ◽  
Healing Property ◽  
Sol Gel Transition

Self-healing hydrogels have drawngreat attention in the past decade since the self-healing property is one of the characteristics of living creatures. In this study, poly(acrylamide-stat-diacetone acrylamide) P(AM-stat-DAA) with a pendant ketone group was synthesized from easy accessible monomers, and thermo-responsive self-healing hydrogels were prepared through a series of diacylhydrazide compounds cross-linking without any additional stimulus. Although the copolymers do not show thermo-response, the hydrogels became thermo-responsive andboth the lower critical solution temperature (LCST) and upper critical solution temperature (UCST) varied with the composition of the copolymer and structure of cross-linkers. With a dynamic covalent bond connection, the hydrogel showed gel-sol-gel transition triggered by acidity, redox, and ketone to acylhydrazide group ratios. This is another interesting cross-linking induced thermo-responsive (CIT) hydrogel with different properties compared to PNIPAM-based thermo-responsive hydrogels. The self-healing hydrogel with CIT properties could have great potential for application in areas related to bioscience, life simulation, and temperature switching.

scholarly journals Phase Transition Behavior of HPMC-AA and Preparation of HPMC-PAA Nanogels

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Risheng Yao ◽  
Jiajia Xu ◽  
Xihua Lu ◽  
Shengsong Deng
Keyword(s):  
Phase Transition ◽  
Driving Force ◽  
Hydroxypropyl Methylcellulose ◽  
Solution Temperature ◽  
Temperature Phase ◽  
Phase Transition Behavior ◽  
Critical Solution Temperature ◽  
Transmission Electron ◽  
Temperature Phase Transition ◽  
Redox Initiator

The lower critical solution temperature (LCST) of hydroxypropyl methylcellulose (HPMC) under mixing with acrylic acid (AA) monomer has been studied by turbidity measurements. It has been found that the LCST of the HPMC was drastically reduced from 60°C to 38°C with the increase of the concentration of AA, while the HPMC is kept at 0.5 wt%. The driving force shifting the LCST is attributed to the hydrogen bonding and hydrophobic interaction of the molecules. Then surfactant-free HPMC-PAA nanogels have been synthesized via the polymerization of AA monomer with the collapsed HPMC as a template or core at their LCST, using KPS and TEMED as redox initiator in the presence of BIS as cross-linking agent. HPMC-PAA nanogels have 50~150  nm diameters characterized by transmission electron microscope and dynamic light scattering. The HPMC-PAA nanogels exhibit the temperature phase transition behaviors, and these nanogels' volume phase transition temperature is close to the LCST of HPMC/AA system.

Polymer chain collapse near the lower critical solution temperature

1997 ◽  
Vol 278 (4-6) ◽  
pp. 302-306 ◽  
Author(s):  
Gabriel Luna-Bárcenas ◽  
Dmitry G. Gromov ◽  
J.Carson Meredith ◽  
Isaac C. Sanchez ◽  
Juan J. de Pablo ◽  
...  
Keyword(s):  
Polymer Chain ◽  
Lower Critical Solution Temperature ◽  
Solution Temperature ◽  
Critical Solution Temperature

Influence of Temperature and the BZ Substrate on Aggregation-Disaggregation Self-Oscillation of a Polymer Chain

2011 ◽  
Vol 467-469 ◽  
pp. 1472-1477
Author(s):  
Yusuke Hara ◽  
Rumana A. Jahan
Keyword(s):  
Polymer Solution ◽  
Polymer Chain ◽  
Life Time ◽  
The Self ◽  
The Other ◽  
Sodium Bromate ◽  
Bz Reaction ◽  
Influence Of Temperature ◽  
Other Hand ◽  
Increasing Temperature

We synthesized a self-oscillating polymer chain with a negatively charged moiety. The polymer chain caused the aggregation-disaggregation self-oscillation under the constant temperature induced by the Belousov-Zhabotinsky (BZ) reaction. In this study, we investigated the influence of temperature and the concentration of sodium bromate on the aggregation-disaggregation self-oscillation of the polymer solution (1.0 wt%) in a strongly acidic condition. As a consequence, we clarified that the life-time of the self-oscillation increased with decrease in the concentration of sodium bromate. On the other hand, the lifetime of the self-oscillation decreased with increase in temperature. In high temperature condition (48 and 60 °C), the amplitude of the self-oscillation was significantly inhomogeneous. Moreover, the frequency of the self-oscillation increased with increasing temperature. On the other hand, the frequency decreased with increase in the concentration of sodium bromate. This tendency was opposite to that in the acid-free condition and the 2.0 wt% AMPS-containing polymer solution.

scholarly journals PECULIARITIES OF REPRODUCTION OF EMOTIONAL SPEECH OF THE CHARACTER IN THE NOVEL «EXTREMELY LOUD AND INCREDIBLY CLOSE» BY J.S. FOYER

2021 ◽  
Author(s):  
U.I. Tykha ◽  
T.L. Marchuk
Keyword(s):  
The Novel ◽  
Main Character ◽  
Careful Selection ◽  
Emotional Speech ◽  
Emotional Tone ◽  
Lexical Semantic ◽  
Methods Of Analysis ◽  
Sporadic Cases ◽  
Translation Methods ◽  
Selection Of

The paper deals with the study of the emotional speech of the character and the emotiveness of the novel "Extremely Loud and Incredibly Close" by J. S. Foyer. Relying on the anthropocentric paradigm, linguistic-stylistic and linguopoetic methods of analysis, linguostylistic means of emotiveness have been analyzed and the main emothemes of the novel have been determined. The whole range of emotions of the main character of the novel under study is expressed in a number of emothemes: shame, anger, embarrassment, panic, anger, aggression, guilt, sadness, disappointment, happiness, relief, joy, comfort. It is shown that translation of emotional speech entails the careful selection of appropriate lexical-semantic, syntactic and stylistic means for adequate reproduction of emotionally marked micro and macro contexts. With the help of descriptive and comparative translation methods, the peculiarities of reproducing the emotiveness of the novel in the Ukrainian translation were revealed. The task of the translator of the emotionally marked speech of the character is to adequately reproduce the thoughts and emotions of the characters in order to evoke in the reader of the translation the same empathy as in the reader of the original. The translator of the novel under study exploits grammatical transformations, decompression, various lexical and semantic changes to adequately reproduce the emotional speech of the main character in J.S. Foyer's novel "Extremely Loud and Incredibly close" in the Ukrainian translation. The study also revealed sporadic cases of non-preservation of emotional connotation and alteration of stylistic mode, which led to semantic-emotional losses. It is concluded that the Ukrainian translation in most cases adequately preserves the emotional tone of the story, and the translation of key repetitions of adverbial intensifiers harmoniously correlates with the title of the novel and sets the expressiveemotional leitmotif of the whole novel.

scholarly journals Logística del cambio en Instituciones Educativas con hoja de cálculo

2019 ◽  
pp. 17-26
Author(s):  
Temístocles Muñoz-Lopez ◽  
Marta Nieves Espericueta-Medina ◽  
Lilia Sánchez-Rivera ◽  
Gabriela Morán-Delgado
Keyword(s):  
Higher Education ◽  
Continuous Improvement ◽  
The Self ◽  
Educational Institutions ◽  
Master's Program ◽  
Careful Selection ◽  
Self Evaluation ◽  
Institutional Evaluation ◽  
Selection Of

The accreditation and certification processes are an imperative of the institutional evaluative culture, taking its foundations in the research methodology, with a careful selection of the variables under study and the analytical categories that support it. This study aims to elucidate the categories in which the institutional evaluation rests, its sources, and its derivation in attributes to be evaluated, a process prior to the elaboration of the SWOT diagnosis. The concentrate of the areas subject to institutional evaluation described and elucidated is presented as the limit of the present work with the objective of developing a technique that allows to carry out the institutional evaluation and with it the strategic planning in the schools or higher education institutions to reach the quality of continuous improvement processes, using in both cases (diagnosis and planning) a spreadsheet. The technique was successfully tested in the self-evaluation of a Master's Program in Education Sciences of the Autonomous University of Coahuila to integrate it to the self-evaluation of the information requested by the accrediting bodies. This technique is useful for educational institutions that do not have sophisticated programs to change and adapt to new educative realities.

Trasmittance Self-Oscillating Behavior of a Non-Thermoresponsive Polymer Chain Induced by the Belouzov-Zhabotinsky (BZ) Reaction

2011 ◽  
Vol 480-481 ◽  
pp. 369-374 ◽  
Author(s):  
Yusuke Hara
Keyword(s):  
Polymer Chain ◽  
Main Chain ◽  
Ruthenium Catalyst ◽  
The Self ◽  
Thermoresponsive Polymer ◽  
Bz Reaction ◽  
Covalently Bonded ◽  
Selection Of

In this study, the influence of the temperature on the transmittance self-oscillation of a non-thermoresponsive polymer chain was investigated. The polymer chain was composed of a biocompatible and non-thermoresponsive poly-vinylpyrrolidone (PVP) main-chain covalently-bonded to the 10 wt% ruthenium catalyst moiety (Ru(bpy)3) of the BZ reaction. As a result, the amplitude of the transmittance self-oscillation slightly decreased with the increase in the temperature. The period of the transmittance self-oscillation decreased with increasing the temperature in accordance with the Arrenius equation. Therefore, the period of the self-oscillation can be controlled by the selection of the temperature.

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