scholarly journals A Review on Current Trends of Polymers in Orthodontics: BPA-Free and Smart Materials

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1409
Author(s):  
Rozita Hassan ◽  
Muhammad Umar Aslam Khan ◽  
Abdul Manaf Abdullah ◽  
Saiful Izwan Abd Razak
Keyword(s):  
Bisphenol A ◽  
Smart Materials ◽  
Endocrine Disruptor ◽  
Polymeric Materials ◽  
Dental Composites ◽  
Current Trends ◽  
Oral Environment ◽  
Recent Developments ◽  
Potential Applications ◽  
Future Utility

Polymeric materials have always established an edge over other classes of materials due to their potential applications in various fields of biomedical engineering. Orthodontics is an emerging field in which polymers have attracted the enormous attention of researchers. In particular, thermoplastic materials have a great future utility in orthodontics, both as aligners and as retainer appliances. In recent years, the use of polycarbonate brackets and base monomers bisphenol A glycerolate dimethacrylate (bis-GMA) has been associated with the potential release of bisphenol A (BPA) in the oral environment. BPA is a toxic compound that acts as an endocrine disruptor that can affect human health. Therefore, there is a continuous search for non-BPA materials with satisfactory mechanical properties and an esthetic appearance as an alternative to polycarbonate brackets and conventional bis-GMA compounds. This study aims to review the recent developments of BPA-free monomers in the application of resin dental composites and adhesives. The most promising polymeric smart materials are also discussed for their relevance to future orthodontic applications.

Novel Behavior in Smart Polymeric Materials: Stress Memory and its Potential Applications

2016 ◽  
Vol 97 ◽  
pp. 93-99
Author(s):  
Jin Lian Hu ◽  
Harishkumar Narayana
Keyword(s):  
Magnetic Field ◽  
Shape Memory ◽  
Smart Materials ◽  
Shape Memory Polymers ◽  
Polymeric Materials ◽  
External Stimulus ◽  
Artificial Muscles ◽  
Recovery Stress ◽  
Stress Memory ◽  
Potential Applications

Materials, structures and systems, responsive to an external stimulus are smart and adaptive to our human demands. Among smart materials, polymers with shape memory effect are at the forefront of research leading to comprehensive publications and wide applications. In this paper, we extend the concept of shape memory polymers to stress memory ones, which have been discovered recently. Like shape memory, stress memory represents a phenomenon where the stress in a polymer can be programmed, stored and retrieved reversibly with an external stimulus such as temperature and magnetic field. Stress memory may be mistaken as the recovery stress which was studied quite broadly. Our further investigation also reveals that stress memory is quite different from recovery stress containing multi-components including elastic and viscoelastic forces in addition to possible memory stress. Stress memory could be used into applications such as sensors, pressure garments, massage devices, electronic skins and artificial muscles. The current revelation of stress memory potentials is emanated from an authentic application of memory fibres, films, and foams in the smart compression devices for the management of chronic and therapeutic disorders.

A review on electroactive polymers development for aerospace applications

2018 ◽  
Vol 29 (19) ◽  
pp. 3681-3695 ◽  
Author(s):  
Musavir Bashir ◽  
Parvathy Rajendran
Keyword(s):  
Smart Materials ◽  
Electroactive Polymers ◽  
Fast Response ◽  
Polymer Materials ◽  
Electroactive Polymer ◽  
Sensors And Actuators ◽  
Aerospace Applications ◽  
Current Trends ◽  
Potential Applications ◽  
Active Flap

Newfangled smart materials have inspired the researchers to look for more efficient materials that can respond to specific stimuli and retain the original shape. Electroactive polymers are such materials which are capable of sensing and real-time actuation. Various electroactive polymers are excellent candidates due to high strain rate, fast response, reliability and high mechanical compliance despite tough manufacturing. In this study, electroactive polymers are reviewed and the general enabling mechanisms employing their distinct characteristics are presented, and the factors influencing the properties of various electroactive polymers are also discussed. Our study also enumerates the current trends in the development of electroactive polymers along with its progress in aerospace discipline. The electromechanical properties of electroactive polymer materials endow them the capability to work as both sensors and actuators in the field of aerospace. Hence, we provide an overview of various applications of electroactive polymers in aerospace field, notably aircraft morphing. These actuators are vastly used in aerospace applications like Mars Nano-rover, space robotic, flapping wings and active flap. Therefore, the electroactive polymer applications such as effective actuators can be investigated more in their materials, molecular interactions, electromechanics and actuation mechanisms. Considering electroactive polymers unique properties, they will endeavour the great potential applications within aerospace industry.

Recent developments in self-oscillating polymeric systems as smart materials: from polymers to bulk hydrogels

2017 ◽  
Vol 4 (1) ◽  
pp. 38-54 ◽  
Author(s):  
Youn Soo Kim ◽  
Ryota Tamate ◽  
Aya Mizutani Akimoto ◽  
Ryo Yoshida
Keyword(s):  
Chemical Reaction ◽  
Smart Materials ◽  
Functional Materials ◽  
Polymeric Materials ◽  
Synthetic Polymers ◽  
Bz Reaction ◽  
Polymeric Systems ◽  
Recent Developments ◽  
Oscillating Chemical Reaction

As novel functional materials, we developed self-oscillating polymeric materials composed of synthetic polymers coupled with an oscillating chemical reaction, the so-called Belousov–Zhabotinsky (BZ) reaction.

Recent Developments of Ambulatory Assessment Methods

2014 ◽  
Vol 25 (4) ◽  
pp. 279-287 ◽  
Author(s):  
Stefan Hey ◽  
Panagiota Anastasopoulou ◽  
André Bideaux ◽  
Wilhelm Stork
Keyword(s):  
Real Time ◽  
Information And Communication Technologies ◽  
New Technologies ◽  
Psychological Research ◽  
Ambulatory Assessment ◽  
Emotional States ◽  
Recent Developments ◽  
Potential Applications ◽  
Information And Communication ◽  
Physiological Sensors

Ambulatory assessment of emotional states as well as psychophysiological, cognitive and behavioral reactions constitutes an approach, which is increasingly being used in psychological research. Due to new developments in the field of information and communication technologies and an improved application of mobile physiological sensors, various new systems have been introduced. Methods of experience sampling allow to assess dynamic changes of subjective evaluations in real time and new sensor technologies permit a measurement of physiological responses. In addition, new technologies facilitate the interactive assessment of subjective, physiological, and behavioral data in real-time. Here, we describe these recent developments from the perspective of engineering science and discuss potential applications in the field of neuropsychology.

Novel organic, polymeric materials for electronics applications

2002 ◽  
Vol 722 ◽  
Author(s):  
Ram W. Sabnis ◽  
Mary J. Spencer ◽  
Douglas J. Guerrero
Keyword(s):  
Optical Density ◽  
Chemical Vapor ◽  
Polymeric Materials ◽  
Substantial Improvement ◽  
Polymeric Systems ◽  
Patterned Wafers ◽  
Visible Spectra ◽  
Potential Applications ◽  
Deep Ultraviolet ◽  
Deposited Films

AbstractNovel organic, polymeric materials and processes of depositing thin films on electronics substrates by chemical vapor deposition (CVD) have been developed and the lithographic behavior of photoresist coated over these CVD films at deep ultraviolet (DUV) wavelength has been evaluated. The specific monomers synthesized for DUV applications include [2.2](1,4)- naphthalenophane, [2.2](9,10)-anthracenophane and their derivatives which showed remarkable film uniformity on flat wafers and conformality over structured topography wafers, upon polymerization by CVD. The chemical, physical and optical properties of the deposited films have been characterized by measuring parameters such as thickness uniformity, solubility, conformality, adhesion to semiconductor substrates, ultraviolet-visible spectra, optical density, optical constants, defectivity, and resist compatibility. Scanning electron microscope (SEM) photos of cross-sectioned patterned wafers showed verticle profiles with no footing, standing waves or undercut. Resist profiles down to 0.10 νm dense lines and 0.09 νm isolated lines were achieved in initial tests. CVD coatings generated 96-100% conformal films, which is a substantial improvement over commercial spin-on polymeric systems. The light absorbing layers have high optical density at 248 nm and are therefore capable materials for DUV lithography applications. CVD is a potentially useful technology to extend lithography for sub-0.15 νm devices. These films have potential applications in microelectronics, optoelectronics and photonics.

scholarly journals Russia’s Foreign Policy Evolution in the New Balkan Landscape

2020 ◽  
Vol 56 (3-4) ◽  
pp. 179-199
Author(s):  
Ekaterina Entina ◽  
Alexander Pivovarenko
Keyword(s):  
Foreign Policy ◽  
Soviet Union ◽  
Regional Security ◽  
Southeast Europe ◽  
The Balkans ◽  
Current Trends ◽  
The Soviet Union ◽  
Recent Developments ◽  
The Difference

The article reflects on the issue of the foreign policy strategy of modern Russia in the Balkans region. One of the most significant aspects of this problem is the difference in views between Russia and the West. Authors show how different interpretations of the events in former Yugoslavia in the 1990s and the beginning of the 2000s predetermined the sense of mutual suspicion and mistrust which spread to other regions such as the post-Soviet space. Exploring differences between the Russian and the Western (Euro-Atlantic) views on the current matters, authors draw attention to fundamental differences in terminology: while the Western narrative promotes more narrow geographical and political definitions (such as the Western Balkan Six), traditional Russian experts are more inclined to wider or integral definitions such as “the Balkans” and “Central and Southeast Europe”. Meanwhile none of these terms are applicable for analysis of the current trends such as the growing transit role of the Balkans region and its embedding in the European regional security architecture. Therefore, a new definition is needed to overcome the differences in vision and better understand significant recent developments in the region. Conceptualizing major foreign policy events in Central and Southeast Europe during the last three decades (the 1990s, 2000s and 2010s), authors demonstrate the significance of differences in tools and methods between the Soviet Union and the modern Russia. Permanent need for adaptation to changing political and security context led to inconsistence in Russian Balkan policy in the 1990s. Nevertheless, Russia was able to preserve an integral vision of the region and even to elaborate new transregional constructive projects, which in right political circumstances may promote stability and become beneficial for both Russia and the Euro-Atlantic community.

scholarly journals Nondegenerate Bright Solitons in Coupled Nonlinear Schrödinger Systems: Recent Developments on Optical Vector Solitons

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 258
Author(s):  
S. Stalin ◽  
R. Ramakrishnan ◽  
M. Lakshmanan
Keyword(s):  
Propagation Constant ◽  
Short Wave ◽  
Nonlinear Phenomena ◽  
Bilinear Method ◽  
Nonlinear Schrödinger ◽  
Bright Solitons ◽  
Nonlinear Schrödinger Systems ◽  
Recent Developments ◽  
Potential Applications ◽  
Photorefractive Materials

Nonlinear dynamics of an optical pulse or a beam continue to be one of the active areas of research in the field of optical solitons. Especially, in multi-mode fibers or fiber arrays and photorefractive materials, the vector solitons display rich nonlinear phenomena. Due to their fascinating and intriguing novel properties, the theory of optical vector solitons has been developed considerably both from theoretical and experimental points of view leading to soliton-based promising potential applications. Mathematically, the dynamics of vector solitons can be understood from the framework of the coupled nonlinear Schrödinger (CNLS) family of equations. In the recent past, many types of vector solitons have been identified both in the integrable and non-integrable CNLS framework. In this article, we review some of the recent progress in understanding the dynamics of the so called nondegenerate vector bright solitons in nonlinear optics, where the fundamental soliton can have more than one propagation constant. We address this theme by considering the integrable two coupled nonlinear Schrödinger family of equations, namely the Manakov system, mixed 2-CNLS system (or focusing-defocusing CNLS system), coherently coupled nonlinear Schrödinger (CCNLS) system, generalized coupled nonlinear Schrödinger (GCNLS) system and two-component long-wave short-wave resonance interaction (LSRI) system. In these models, we discuss the existence of nondegenerate vector solitons and their associated novel multi-hump geometrical profile nature by deriving their analytical forms through the Hirota bilinear method. Then we reveal the novel collision properties of the nondegenerate solitons in the Manakov system as an example. The asymptotic analysis shows that the nondegenerate solitons, in general, undergo three types of elastic collisions without any energy redistribution among the modes. Furthermore, we show that the energy sharing collision exhibiting vector solitons arises as a special case of the newly reported nondegenerate vector solitons. Finally, we point out the possible further developments in this subject and potential applications.

scholarly journals Recent Developments in Lignin- and Tannin-Based Non-Isocyanate Polyurethane Resins for Wood Adhesives—A Review

2021 ◽  
Vol 11 (9) ◽  
pp. 4242
Author(s):  
Manggar Arum Aristri ◽  
Muhammad Adly Rahandi Lubis ◽  
Sumit Manohar Yadav ◽  
Petar Antov ◽  
Antonios N. Papadopoulos ◽  
...  
Keyword(s):  
Automotive Industry ◽  
Polymeric Materials ◽  
Review Article ◽  
Future Perspectives ◽  
Wood Adhesives ◽  
Adhesion Properties ◽  
Lighting Industry ◽  
Renewable Natural Resources ◽  
Recent Developments ◽  
Strong Adhesion

This review article aims to summarize the potential of using renewable natural resources, such as lignin and tannin, in the preparation of NIPUs for wood adhesives. Polyurethanes (PUs) are extremely versatile polymeric materials, which have been widely used in numerous applications, e.g., packaging, footwear, construction, the automotive industry, the lighting industry, insulation panels, bedding, furniture, metallurgy, sealants, coatings, foams, and wood adhesives. The isocyanate-based PUs exhibit strong adhesion properties, excellent flexibility, and durability, but they lack renewability. Therefore, this study focused on the development of non-isocyanate polyurethane lignin and tannin resins for wood adhesives. PUs are commercially synthesized using polyols and polyisocyanates. Isocyanates are toxic, costly, and not renewable; thus, a search of suitable alternatives in the synthesis of polyurethane resins is needed. The reaction with diamine compounds could result in NIPUs based on lignin and tannin. The research on bio-based components for PU synthesis confirmed that they have good characteristics as an alternative for the petroleum-based adhesives. The advantages of improved strength, low curing temperatures, shorter pressing times, and isocyanate-free properties were demonstrated by lignin- and tannin-based NIPUs. The elimination of isocyanate, associated with environmental and human health hazards, NIPU synthesis, and its properties and applications, including wood adhesives, are reported comprehensively in this paper. The future perspectives of NIPUs’ production and application were also outlined.

scholarly journals Extracellular Vesicles: Novel Opportunities to Understand and Detect Neoplastic Diseases

2021 ◽  
pp. 030098582199932
Author(s):  
Laura Bongiovanni ◽  
Anneloes Andriessen ◽  
Marca H. M. Wauben ◽  
Esther N. M. Nolte-’t Hoen ◽  
Alain de Bruin
Keyword(s):  
Extracellular Vesicles ◽  
Biologically Active ◽  
Liquid Biopsies ◽  
Donor Cells ◽  
Recent Developments ◽  
Veterinary Pathology ◽  
Cell Components ◽  
Potential Applications ◽  
Intercellular Communications

With a size range from 30 to 1000 nm, extracellular vesicles (EVs) are one of the smallest cell components able to transport biologically active molecules. They mediate intercellular communications and play a fundamental role in the maintenance of tissue homeostasis and pathogenesis in several types of diseases. In particular, EVs actively contribute to cancer initiation and progression, and there is emerging understanding of their role in creation of the metastatic niche. This fact underlies the recent exponential growth in EV research, which has improved our understanding of their specific roles in disease and their potential applications in diagnosis and therapy. EVs and their biomolecular cargo reflect the state of the diseased donor cells, and can be detected in body fluids and exploited as biomarkers in cancer and other diseases. Relatively few studies have been published on EVs in the veterinary field. This review provides an overview of the features and biology of EVs as well as recent developments in EV research including techniques for isolation and analysis, and will address the way in which the EVs released by diseased tissues can be studied and exploited in the field of veterinary pathology. Uniquely, this review emphasizes the important contribution that pathologists can make to the field of EV research: pathologists can help EV scientists in studying and confirming the role of EVs and their molecular cargo in diseased tissues and as biomarkers in liquid biopsies.

Metaphor Research and the Hebrew Bible

2021 ◽  
Vol 19 (3) ◽  
pp. 235-285
Author(s):  
Mason D. Lancaster
Keyword(s):  
Hebrew Bible ◽  
Conceptual Metaphor ◽  
Future Research ◽  
Conceptual Metaphor Theory ◽  
Current Trends ◽  
Metaphor Theory ◽  
Recent Developments

This article provides an overview of metaphor theories and research on their own terms, as well as their use in Hebrew Bible (HB) studies. Though metaphor studies in the HB have become increasingly popular, they often draw upon a limited or dated subset of metaphor scholarship. The first half of this article surveys a wide variety of metaphor scholarship from the humanities (philosophical, poetic, rhetorical) and the sciences (e.g., conceptual metaphor theory), beginning with Aristotle but focusing on more recent developments. The second half overviews studies of metaphor in the HB since 1980, surveying works focused on theory and method; works focused on specific biblical books or metaphor domains; and finally noting current trends and suggesting areas for future research.

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