scholarly journals Dual-Layer Approach toward Self-Healing and Self-Cleaning Polyurethane Thermosets

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1849 ◽  
Author(s):  
Muhammad Naveed ◽  
Muhammad Rabnawaz ◽  
Ajmir Khan ◽  
Mohammad O. Tuhin
Keyword(s):  
Bottom Layer ◽  
Dip Coating ◽  
The Self ◽  
Self Healing ◽  
Characterization Methods ◽  
Novel Approach ◽  
Wide Range ◽  
Self Cleaning ◽  
Prepared Layer

There is an urgent need for coatings that exhibit both self-healing as well as self-cleaning properties as they can be used for a wide range of applications. Herein we report a novel approach toward fabricating polyurethane thermosets possessing both self-cleaning and self-healing properties. The desired coating was achieved via casting a bottom layer of self-healable polyurethanes comprised of reversible phenolic urethane bonds followed by a subsequent dip-coating of the prepared layer in a solution of bis(3-aminopropyl)-terminated polydimethylsiloxane (PDMS-NH2). The PDMS was used to impart self-cleaning properties to the coating. While the self-healing behavior of the bottom polyurethane layer is achieved through phenolic urethane chemistry, via the exchange of phenolic urethane moieties. The prepared coatings were tested for their optical, mechanical, self-healing, and self-cleaning properties using a variety of characterization methods, which confirmed the successful fabrication of novel self-cleaning and self-healing clear urethane coatings.

scholarly journals Preparation and Characterization of Isosorbide-Based Self-Healable Polyurethane Elastomers with Thermally Reversible Bonds

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1061 ◽  
Author(s):  
Han-Na Kim ◽  
Dae-Woo Lee ◽  
Hoon Ryu ◽  
Gwang-Seok Song ◽  
Dai-Soo Lee
Keyword(s):  
Elevated Temperatures ◽  
Phenyl Isocyanate ◽  
Chain Extender ◽  
The Self ◽  
Self Healing ◽  
Polyurethane Elastomers ◽  
Wide Range ◽  
Chain Extenders ◽  
Product Durability

Polyurethane (PU) is a versatile polymer used in a wide range of applications. Recently, imparting PU with self-healing properties has attracted much interest to improve the product durability. The self-healing mechanism conceivably occurs through the existence of dynamic reversible bonds over a specific temperature range. The present study investigates the self-healing properties of 1,4:3,6-dianhydrohexitol-based PUs prepared from a prepolymer of poly(tetra-methylene ether glycol) and 4,4′-methylenebis(phenyl isocyanate) with different chain extenders (isosorbide or isomannide). PU with the conventional chain extender 1,4-butanediol was prepared for comparison. The urethane bonds in 1,4:3,6-dianhydrohexitol-based PUs were thermally reversible (as confirmed by the generation of isocyanate peaks observed by Fourier transform infrared spectroscopy) at mildly elevated temperatures and the PUs showed good mechanical properties. Especially the isosorbide-based polyurethane showed potential self-healing ability under mild heat treatment, as observed in reprocessing tests. It is inferred that isosorbide, bio-based bicyclic diol, can be employed as an efficient chain extender of polyurethane prepolymers to improve self-healing properties of polyurethane elastomers via reversible features of the urethane bonds.

A Comparison of Physiological Demand between Self-Propelled and Motorized Treadmill Exercise

2018 ◽  
Vol 7 (4) ◽  
pp. 13-21
Author(s):  
Todd Backes ◽  
Charlene Takacs
Keyword(s):  
Respiratory Exchange Ratio ◽  
Treadmill Exercise ◽  
Cardiopulmonary Exercise Testing ◽  
Mean Value ◽  
The Self ◽  
Mixing Chamber ◽  
Wide Range ◽  
The Subject ◽  
The Mean ◽  
Computer Controlled

There are a wide range of options for individuals to choose from in order to engage in aerobic exercise; from outdoor running to computer controlled and self-propelled treadmills. Recently, self-propelled treadmills have increased in popularity and provide an alternative to a motorized treadmill. Twenty subjects (10 men, 10 women) ranging in age from 19-23 with a mean of 20.4 ± 0.8 SD were participants in this study. The subjects visited the laboratory on three occasions. The purpose of the first visit was to familiarize the subject with the self-propelled treadmill (Woodway Curve 3.0). The second visit, subjects were instructed to run on the self-propelled treadmill for 3km at a self-determined pace. Speed data were collected directly from the self-propelled treadmill. The third visit used speed data collected during the self-propelled treadmill run to create an identically paced 3km run for the subjects to perform on a motorized treadmill (COSMED T150). During both the second and third visit, oxygen consumption (VO2) and respiratory exchange ratio (R) data were collected with COSMED’s Quark cardiopulmonary exercise testing (CPET) metabolic mixing chamber system. The VO2 mean value for the self-propelled treadmill (44.90 ± 1.65 SE ml/kg/min) was significantly greater than the motorized treadmill (34.38 ± 1.39 SE ml/kg/min). The mean R value for the self-propelled treadmill (0.91 ± 0.01 SE) was significantly greater than the motorized treadmill (0.86 ± 0.01 SE). Our study demonstrated that a 3km run on a self-propelled treadmill does elicit a greater physiological response than a 3km run at on a standard motorized treadmill. Self-propelled treadmills provide a mode of exercise that offers increased training loads and should be considered as an alternative to motorized treadmills.

Anodic voltammetry of pyrazolone derivatives with the help of the self-cleaning rotating electrode

1987 ◽  
Vol 52 (1) ◽  
pp. 66-71 ◽  
Author(s):  
Vesselin C. Noninski ◽  
Emanuel B. Sobowale
Keyword(s):  
Electrochemical Oxidation ◽  
The Self ◽  
Good Reproducibility ◽  
Rotating Electrode ◽  
Pyrazolone Derivatives ◽  
Self Cleaning ◽  
Anodic Voltammetry

Nine pyrazolone derivatives have been studied by anodic voltammetry using gold self-cleaning rotating electrode (SRE). Voltamograms of good reproducibility are presented. On the basis of voltammetric data a mechanism is proposed for the electrochemical oxidation of sodium 1-phenyl-2,3-dimethyl-4-(N-methylamino)pyrazol-5-one-N-methansulphonate and 1-phenyl-2,3-dimethyl-4-(dimethylamino)pyrazol-5-one in protic medium.

Expressing the Self

2018 ◽  
Keyword(s):  
Philosophy Of Mind ◽  
The Self ◽  
Epistemic Status ◽  
First Person ◽  
Semantic Categories ◽  
Wide Range ◽  
Person Reference ◽  
De Se ◽  
Novel Method ◽  
Cultural Pragmatics

This book addresses different linguistic and philosophical aspects of referring to the self in a wide range of languages from different language families, including Amharic, English, French, Japanese, Korean, Mandarin, Newari (Sino-Tibetan), Polish, Tariana (Arawak), and Thai. In the domain of speaking about oneself, languages use a myriad of expressions that cut across grammatical and semantic categories, as well as a wide variety of constructions. Languages of Southeast and East Asia famously employ a great number of terms for first-person reference to signal honorification. The number and mixed properties of these terms make them debatable candidates for pronounhood, with many grammar-driven classifications opting to classify them with nouns. Some languages make use of egophors or logophors, and many exhibit an interaction between expressing the self and expressing evidentiality qua the epistemic status of information held from the ego perspective. The volume’s focus on expressing the self, however, is not directly motivated by an interest in the grammar or lexicon, but instead stems from philosophical discussions of the special status of thoughts about oneself, known as de se thoughts. It is this interdisciplinary understanding of expressing the self that underlies this volume, comprising philosophy of mind at one end of the spectrum and cross-cultural pragmatics of self-expression at the other. This unprecedented juxtaposition results in a novel method of approaching de se and de se expressions, in which research methods from linguistics and philosophy inform each other. The importance of this interdisciplinary perspective on expressing the self cannot be overemphasized. Crucially, the volume also demonstrates that linguistic research on first-person reference makes a valuable contribution to research on the self tout court, by exploring the ways in which the self is expressed, and thereby adding to the insights gained through philosophy, psychology, and cognitive science.

Charles Olson and American Modernism

2018 ◽  
Author(s):  
Mark Byers
Keyword(s):  
New York ◽  
Political Action ◽  
The Self ◽  
Instrumental Reason ◽  
Charles Olson ◽  
American Modernism ◽  
Avant Garde ◽  
Wide Range ◽  
American Poet ◽  
Mark Rothko

The Practice of the Self situates the work of American poet Charles Olson (1910–70) at the centre of the early postwar American avant-garde. It shows Olson to have been one of the major advocates and theorists of American modernism in the late 1940s and early 1950s; a poet who responded fully and variously to the political, ethical, and aesthetic urgencies driving innovation across contemporary American art. Reading Olson’s work alongside that of contemporaries associated with the New York Schools of painting and music (as well as the exiled Frankfurt School), the book draws on Olson’s published and unpublished writings to establish an original account of early postwar American modernism. The development of Olson’s work is seen to illustrate two primary drivers of formal innovation in the period: the evolution of a new model of political action pivoting around the radical individual and, relatedly, a powerful new critique of instrumental reason and the Enlightenment tradition. Drawing on extensive archival research and featuring readings of a wide range of artists—including, prominently, Barnett Newman, Mark Rothko, David Smith, Wolfgang Paalen, and John Cage—The Practice of the Self offers a new reading of a major American poet and an original account of the emergence of postwar American modernism.

Interpretation In Qualitative Research: What, Why, How

2020 ◽  
pp. 955-982
Author(s):  
Allen Trent ◽  
Jeasik Cho
Keyword(s):  
Qualitative Research ◽  
Qualitative Inquiry ◽  
The Self ◽  
Validity Evidence ◽  
Wide Range ◽  
Interpretive Strategies

This chapter addresses a wide range of concepts related to interpretation in qualitative research, examines the meaning and importance of interpretation in qualitative inquiry, and explores the ways methodology, data, and the self/researcher as instrument interact and impact interpretive processes. Additionally, the chapter presents a series of strategies for qualitative researchers engaged in the process of interpretation and closes by presenting a framework for qualitative researchers designed to inform their interpretations. The framework includes attention to the key qualitative research concepts transparency, reflexivity, analysis, validity, evidence, and literature. Four questions frame the chapter: What is interpretation, and why are interpretive strategies important in qualitative research? How do methodology, data, and the researcher/self impact interpretation in qualitative research? How do qualitative researchers engage in the process of interpretation? And, in what ways can a framework for interpretation strategies support qualitative researchers across multiple methodologies and paradigms?

scholarly journals Responsive and Personalized Web Layouts with Integer Programming

2021 ◽  
Vol 5 (EICS) ◽  
pp. 1-23
Author(s):  
Markku Laine ◽  
Yu Zhang ◽  
Simo Santala ◽  
Jussi P. P. Jokinen ◽  
Antti Oulasvirta
Keyword(s):  
Integer Programming ◽  
Web Design ◽  
Web Pages ◽  
Web Page Design ◽  
Automated Generation ◽  
Novel Approach ◽  
Wide Range ◽  
Responsive Design ◽  
Responsive Web Design ◽  
Page Design

Over the past decade, responsive web design (RWD) has become the de facto standard for adapting web pages to a wide range of devices used for browsing. While RWD has improved the usability of web pages, it is not without drawbacks and limitations: designers and developers must manually design the web layouts for multiple screen sizes and implement associated adaptation rules, and its "one responsive design fits all" approach lacks support for personalization. This paper presents a novel approach for automated generation of responsive and personalized web layouts. Given an existing web page design and preferences related to design objectives, our integer programming -based optimizer generates a consistent set of web designs. Where relevant data is available, these can be further automatically personalized for the user and browsing device. The paper includes presentation of techniques for runtime adaptation of the designs generated into a fully responsive grid layout for web browsing. Results from our ratings-based online studies with end users (N = 86) and designers (N = 64) show that the proposed approach can automatically create high-quality responsive web layouts for a variety of real-world websites.

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