The experience of operating solar arrays indicates the need to solve the problem of creating effective and reliable switching elements to block defective and damaged photovoltaic cells. Available methods of solving this problem (for example, the use of transistor switches, electronic systems, etc.) either do not completely solve it, or are expensive. The tasks of increasing the reliability and efficiency of switching elements, preventing the destruction of photovoltaic cells which occurs during heating by dark current ("hot spots" and fire hazardous situations) are relevant. Recently, one of the promising solutions of this problem is the use of additional devices for isolating inactive (shaded or defective) areas of both separate photovoltaic cells and their modules. These devices are PPTC (polymeric positive temperature coefficient) resettable fuses of PolySwitch type, which are polymer composites with nanoscale carbon fillers. The basic functional property of PPTC fuse is an abrupt increase in electrical resistance by several orders of magnitude when a temperature is reached and a return to the initial high conductive state when the temperature drops. The advantages of such structures based on polymer composites with nanocarbon fillers include: – close to the metal resistance to the switching temperature and to the resistance of the insulator above the specified temperature; – possibility of realization in the form of discrete elements and continuous film-tapes (that is important at the decision of problems of realization of isolation of defective local area of the separate photovoltaic cell); – reaction in the form of temporary isolation of separate components of the solar array to increase their temperature. The research results are presented and the concept of overload protection by using resettable fuses based on polymer nanocomposite materials with nanocarbon fillers is substantiated in this paper. In particular, the expediency of series connection of PolySwitch fuses to photovoltaic modules with parallel connection of their strings is shown to prevent an abnormal situation, namely, a complete loss of electrical energy generated by such a string, which can occur when one of its modules is short-circuited. The circuit solutions in the form of combined structure based on layers of a varistor ceramics and a posistor polymer nanocomposite with carbon filler being in thermal contact are investigated. The prospect of its use to protect photovoltaic cells with a high reverse resistance from overvoltage is established. The problem of protection against local overheating in photovoltaic cells (or their parallel connections) by physical and technological methods, in particular, by creating photovoltaic cells with a built-in layer based on a posistor composite being in thermal contact with it, is analyzed. In general, the described results represent a new direction in the field of improving photovoltaic systems, in particular, in terms of increasing their efficiency, operating time and reliability by using solid-state devices based on polymer posistor nanocomposites and varistor ceramics as means of their protection from electrical and thermal overloads. Keywords: SOLAR ARRAY, PHOTOVOLTAIC MODULE, PHOTOVOLTAIC CELL, ELECTRIC OVERLOAD, POLYMER POSISTOR NANOCOMPOSITE, HOT SPOT, VARISTOR CERAMICS

Polymer Nanocomposites for Energy Applications Explore the science of polymer nanocomposites and their practical use in energy applications In Polymer Nanocomposites for Energy Applications, a team of distinguished researchers delivers a comprehensive review of the synthesis and characterization of polymer nanocomposites, as well as their applications in the field of energy. Succinct and insightful, the book explores the storage of electrical, magnetic, and thermal energy and hydrogen. It also discusses energy generation by polymer-based solar cells. Finally, the authors present a life cycle analysis of polymer nanocomposites for energy applications and provide four real-world case studies where these materials have been successfully used. Readers will also find: Thorough introductions to the origins and synthesis of polymer materials In-depth discussions of the characterization of polymeric materials, including UV-visible spectroscopy Comprehensive explorations of a wide variety of polymer material applications, including in biotechnology and for soil remediation Fulsome presentations of polymer nanocomposites and their use in energy storage systems Perfect for materials and engineering scientists and polymer chemists, Polymer Nanocomposites for Energy Applications will also earn a place in the libraries of professionals working in the chemical industry.

Polymer Nanocomposite Materials Discover an authoritative overview of zero-, one-, and two-dimensional polymer nanomaterials Polymer Nanocomposite Materials: Applications in Integrated Electronic Devices delivers an original and insightful treatment of polymer nanocomposite applications in energy, information, and biotechnology. The book systematically reviews the preparation and characterization of polymer nanocomposites from zero-, one-, and two-dimensional nanomaterials. The two distinguished editors have selected resources that thoroughly explore the applications of polymer nanocomposites in energy, information, and biotechnology devices like sensors, solar cells, data storage devices, and artificial synapses. Academic researchers and professional developers alike will enjoy one of the first books on the subject of this environmentally friendly and versatile new technology. Polymer Nanocomposite Materials discusses challenges associated with the devices and materials, possible strategies for future directions of the technology, and the possible commercial applications of electronic devices built on these materials. Readers will also benefit from the inclusion of: A thorough introduction to the fabrication of conductive polymer composites and their applications in sensors An exploration of biodegradable polymer nanocomposites for electronics and polymer nanocomposites for photodetectors Practical discussions of polymer nanocomposites for pressure sensors and the application of polymer nanocomposites in energy storage devices An examination of functional polymer nanocomposites for triboelectric nanogenerators and resistive switching memory Perfect for materials scientists and polymer chemists, Polymer Nanocomposite Materials: Applications in Integrated Electronic Devices will also earn a place in the libraries of sensor developers, electrical engineers, and other professionals working in the sensor industry seeking an authoritative one-stop reference for nanocomposite applications.

An international perspective on the latest research in polymer solar cell technology.

Supercapacitors have drawn intensive attention owing to their virtues of high power density, long cycle life, short charging time and safe operation for promising applications to resolve problems of limited global energy supply and environmental problems. Supercapacitors are designed to bridge the gap between batteries and capacitors, to form fast charging energy-storage devices of intermediate specific energy. The supercapacitor is an important device in the energy storage and conversion systems, and is used in different applications such as in electric vehicles, uninterruptible power supplies, memory protection of computer electronics and cellular devices.This book serves as a guide in understanding the basics of conducting polymer technology, nanostructurisation of conducting polymers and their composites emerging as a new field of research and development, directed to the creation of new smart materials, especially for supercapacitors.The concepts of supercapacitors are well explained in simple and concise form to avoid the confusion of students and academic professionals. The book has chemical engineering orientation and therefore, professionals from the polymer science field may find this book most suitable for their advanced and applied field of research. It will provide them an opportunity to learn about conducting polymers and nanocomposites, and their production and processing technology for supercapacitors. Although the attention is mainly focused on preparation of conducting polymer based binary and ternary nanocomposites and their electrochemical performances for supercapacitor application, this book will be a valuable reference for scientists, engineers, students and general readers who are interested in the investigation and exploitation of the fascinating new class of conducting polymer nanocomposites.

This book covers smart polymer nanocomposites with perspectives for application in energy harvesting, as self-healing materials, or shape memory materials. The book is application-oriented and describes different types of polymer nanocomposites, such as elastomeric composites, thermoplastic composites, or conductive polymer composites. It outlines their potential for applications, which would meet some of the most important challenges nowadays: for harvesting energy, as materials with the capacity to self-heal, or as materials memorizing a given shape.The book brings together these different applications for the first time in one single platform. Chapters are ordered both by the type of composites and by the target applications. Readers will thus find a good overview, facilitating a comparison of the different smart materials and their applications. The book will appeal to scientists in the fields of chemistry, material science and engineering, but also to technologists and physicists, from graduate student level to researcher and professional.

An exciting new technology, described by the one who invented it This is the first book dedicated to cognitive radio, a promising new technology that is poised to revolutionize the telecommunications industry with increased wireless flexibility. Cognitive radio technology integrates computational intelligence into software-defined radio for embedded intelligent agents that adapt to RF environments and user needs. Using this technology, users can more fully exploit the radio spectrum and services available from wireless connectivity. For example, an attempt to send a 10MB e-mail in a zone where carrier charges are high might cause a cognitive radio to alert its user and suggest waiting until getting to the office to use the LAN instead. Cognitive Radio Architecture examines an "ideal cognitive radio" that features autonomous machine learning, computer vision, and spoken or written language perception. The author of this exciting new book is the inventor of the technology and a leader in the field. Following his step-by-step introduction, readers can start building aware/adaptive radios and then make steps towards cognitive radio. After an introduction to adaptive, aware, and cognitive radio, the author develops three major themes in three sections: Foundations Radio Competence User Domain Competence The book makes the design principles of cognitive radio more accessible to students of teleinformatics, as well as to wireless communications systems developers. It therefore embraces the practice of cognitive radio as well as the theory. In particular, the publication develops a cognitive architecture that integrates disparate disciplines, including autonomous machine learning, computer vision, and language perception technologies. In addition, for the convenience of the reader, Web resources introducing key concepts such as speech applications programmer interfaces (APIs) are included. Although still five to ten years away from full deployment, telecommunications giants and research labs around the world are already dedicating R&D to this new technology. Telecommunications engineers as well as advanced undergraduate and graduate students can learn the promising possibilities of this innovative technology from the one who invented it.