0
Your cart

Your cart is empty

Browse All Departments
Price
  • R50 - R100 (1)
  • R100 - R250 (131)
  • R250 - R500 (649)
  • R500+ (20,936)
  • -
Status
Format
Author / Contributor
Publisher

Books > Professional & Technical > Energy technology & engineering

Contemporary Research and Cutting-Edge Technology in Electrical Engineering (Hardcover): M V Suganyadevi, R Ramya Contemporary Research and Cutting-Edge Technology in Electrical Engineering (Hardcover)
M V Suganyadevi, R Ramya
R2,312 R1,812 Discovery Miles 18 120 Save R500 (22%) Ships in 10 - 15 working days
Embodied Carbon in Buildings - Measurement, Management, and Mitigation (Hardcover, 1st ed. 2018): Francesco Pomponi, Catherine... Embodied Carbon in Buildings - Measurement, Management, and Mitigation (Hardcover, 1st ed. 2018)
Francesco Pomponi, Catherine De Wolf, Alice Moncaster
R6,205 Discovery Miles 62 050 Ships in 12 - 17 working days

This book provides a single-source reference for whole life embodied impacts of buildings. The comprehensive and persuasive text, written by over 50 invited experts from across the world, offers an indispensable resource both to newcomers and to established practitioners in the field. Ultimately it provides a persuasive argument as to why embodied impacts are an essential aspect of sustainable built environments. The book is divided into four sections: measurement, including a strong emphasis on uncertainty analysis, as well as offering practical case studies of individual buildings and a comparison of materials; management, focusing in particular on the perspective of designers and contractors; mitigation, which identifies some specific design strategies as well as challenges; and finally global approaches, six chapters which describe in authoritative detail the ways in which the different regions of the world are tackling the issue.

Gas Turbine Design, Components and System Design Integration - Second Revised and Enhanced Edition (Hardcover, 2nd ed. 2019):... Gas Turbine Design, Components and System Design Integration - Second Revised and Enhanced Edition (Hardcover, 2nd ed. 2019)
Meinhard T. Schobeiri
R6,862 Discovery Miles 68 620 Ships in 12 - 17 working days

This is the second revised and enhanced edition of the book Gas Turbine Design, Components and System Integration written by a world-renowned expert with more than forty years of active gas turbine R&D experience. It comprehensively treats the design of gas turbine components and their integration into a complete system. Unlike many currently available gas turbine handbooks that provide the reader with an overview without in-depth treatment of the subject, the current book is concentrated on a detailed aero-thermodynamics, design and off-deign performance aspects of individual components as well as the system integration and its dynamic operation. This new book provides practicing gas turbine designers and young engineers working in the industry with design material that the manufacturers would keep proprietary. The book is also intended to provide instructors of turbomachinery courses around the world with a powerful tool to assign gas turbine components as project and individual modules that are integrated into a complete system. Quoting many statements by the gas turbine industry professionals, the young engineers graduated from the turbomachinery courses offered by the author, had the competency of engineers equivalent to three to four years of industrial experience.

Deep In-memory Architectures for Machine Learning (Hardcover, 1st ed. 2020): Mingu Kang, Sujan Gonugondla, Naresh R. Shanbhag Deep In-memory Architectures for Machine Learning (Hardcover, 1st ed. 2020)
Mingu Kang, Sujan Gonugondla, Naresh R. Shanbhag
R2,616 Discovery Miles 26 160 Ships in 12 - 17 working days

This book describes the recent innovation of deep in-memory architectures for realizing AI systems that operate at the edge of energy-latency-accuracy trade-offs. From first principles to lab prototypes, this book provides a comprehensive view of this emerging topic for both the practicing engineer in industry and the researcher in academia. The book is a journey into the exciting world of AI systems in hardware.

Energy Efficiency in the Minerals Industry - Best Practices and Research Directions (Hardcover, 1st ed. 2018): Kwame Awuah-Offei Energy Efficiency in the Minerals Industry - Best Practices and Research Directions (Hardcover, 1st ed. 2018)
Kwame Awuah-Offei
R4,708 R3,568 Discovery Miles 35 680 Save R1,140 (24%) Ships in 12 - 17 working days

This book presents a state-of-the-art analysis of energy efficiency as applied to mining processes. From ground fragmentation to mineral processing and extractive metallurgy, experts discuss the current state of knowledge and the nagging questions that call for further research. It offers an excellent resource for all mine managers and engineers who want to improve energy efficiency to boost both production efficiency and sustainability. It will also benefit graduate students and experienced researchers looking for a comprehensive review of the current state of knowledge concerning energy efficiency in the minerals industry.

Control of Power Electronic Converters and Systems - Volume 2 (Paperback): Frede Blaabjerg Control of Power Electronic Converters and Systems - Volume 2 (Paperback)
Frede Blaabjerg
R3,660 R3,152 Discovery Miles 31 520 Save R508 (14%) Ships in 12 - 17 working days

Control of Power Electronic Converters, Volume Two gives the theory behind power electronic converter control and discusses the operation, modelling and control of basic converters. The main components of power electronics systems that produce a desired effect (energy conversion, robot motion, etc.) by controlling system variables (voltages and currents) are thoroughly covered. Both small (mobile phones, computer power supplies) and very large systems (trains, wind turbines, high voltage power lines) and their power ranges, from the Watt to the Gigawatt, are presented and explored. Users will find a focused resource on how to apply innovative control techniques for power converters and drives.

Recycle Based Organic Agriculture in a City (Hardcover, 1st ed. 2020): Seishu Tojo Recycle Based Organic Agriculture in a City (Hardcover, 1st ed. 2020)
Seishu Tojo
R2,947 Discovery Miles 29 470 Ships in 10 - 15 working days

This book highlights the significance of urban agricultural production, the technologies and methods for supplying organic materials to the farmland, recovering plant nutrients and energy in cities, and systems for sustaining farmlands in order to produce agricultural crops and supply safe food to citizens. Focusing on the effective recycling of biomass waste generated in cities for use in organic farming, it discusses alternatives to traditional composting, such as carbonizing organic waste, which not only produces recyclable materials but also converts organic waste into energy. Recycling discarded organic matter appropriately and reusing it as both material and energy is the basis of new urban organic farming, and represents a major challenge for the next generation of urban agriculture. As such, the book presents advanced research findings to facilitate the implementation of safe, organic agricultural production with only a small environmental load.

AutoCAD Electrical 2022 Black Book (Colored) (Hardcover): Gaurav Verma, Matt Weber AutoCAD Electrical 2022 Black Book (Colored) (Hardcover)
Gaurav Verma, Matt Weber
R1,514 Discovery Miles 15 140 Ships in 12 - 17 working days
Heat Pipe Applications in Fission Driven Nuclear Power Plants (Hardcover, 1st ed. 2019): Bahman Zohuri Heat Pipe Applications in Fission Driven Nuclear Power Plants (Hardcover, 1st ed. 2019)
Bahman Zohuri
R4,824 Discovery Miles 48 240 Ships in 12 - 17 working days

This book presents a new and innovative approach for the use of heat pipes and their application in a number of industrial scenarios, including space and nuclear power plants. The book opens by describing the heat pipe and its concept, including sizing, composition and binding energies. It contains mathematical models of high and low temperature pipes along with extensive design and manufacturing models, characteristics and testing programs. A detailed design and safety analysis concludes the book, emphasizing the importance of heat pipe implementation within the main cooling system and within the core of the reactor, making this book a useful resource for students, engineers, and researchers.

The New World of Utilities - A Historical Transition Towards a New Energy System (Hardcover, 1st ed. 2019): Vincent Petit The New World of Utilities - A Historical Transition Towards a New Energy System (Hardcover, 1st ed. 2019)
Vincent Petit
R1,547 Discovery Miles 15 470 Ships in 10 - 15 working days

After decades of stability, power systems are currently undergoing a rapid transition - demand patterns are evolving, while supply sources are shifting to renewable energies at an accelerated pace. This book, written by an experienced energy professional, combines the various aspects of supply and demand developments to offer a unified perspective. It highlights the key changes that the world of electric utilities and power systems will face in the coming decade, as well as the major challenges that will emerge as a result. Supplemented by a wealth of global and local data, the book describes the major patterns that affect both supply and demand, and provides a quantified analysis of their impacts on power system grids and markets. Lastly, it explores the new technologies that can enable the success of these transformations.

Introduction to Transients in Electrical Circuits - Analytical and Digital Solution Using an EMTP-based Software (Hardcover,... Introduction to Transients in Electrical Circuits - Analytical and Digital Solution Using an EMTP-based Software (Hardcover, 1st ed. 2021)
Jose Carlos Goulart de Siqueira, Benedito Donizeti Bonatto
R2,095 R1,498 Discovery Miles 14 980 Save R597 (28%) Ships in 12 - 17 working days

This book integrates analytical and digital solutions through Alternative Transients Program (ATP) software, recognized for its use all over the world in academia and in the electric power industry, utilizing a didactic approach appropriate for graduate students and industry professionals alike. This book presents an approach to solving singular-function differential equations representing the transient and steady-state dynamics of a circuit in a structured manner, and without the need for physical reasoning to set initial conditions to zero plus (0+). It also provides, for each problem presented, the exact analytical solution as well as the corresponding digital solution through a computer program based on the Electromagnetics Transients Program (EMTP). Of interest to undergraduate and graduate students, as well as industry practitioners, this book fills the gap between classic works in the field of electrical circuits and more advanced works in the field of transients in electrical power systems, facilitating a full understanding of digital and analytical modeling and solution of transients in basic circuits.

Computing Algorithms with Applications in Engineering - Proceedings of ICCAEEE 2019 (Hardcover, 1st ed. 2020): V. K. Giri,... Computing Algorithms with Applications in Engineering - Proceedings of ICCAEEE 2019 (Hardcover, 1st ed. 2020)
V. K. Giri, Nishchal K. Verma, R K Patel, V.P. Singh
R4,499 Discovery Miles 44 990 Ships in 12 - 17 working days

This book collects high-quality research papers presented at the International Conference on Computing Applications in Electrical & Electronics Engineering, held at Rajkiya Engineering College, Sonbhadra, India, on August 30-31, 2019. It provides novel contributions in computational intelligence, together with valuable reference material for future research. The topics covered include: big data analytics, IoT and smart infrastructures, machine learning, artificial intelligence and deep learning, crowd sourcing and social intelligence, natural language processing, business intelligence, high-performance computing, wireless, mobile and green communications, ad-hoc, sensor and mesh networks, SDN and network virtualization, cognitive systems, swarm intelligence, human-computer interaction, network and information security, intelligent control, soft computing, networked control systems, renewable energy sources and technologies, biomedical signal processing, pattern recognition and object tracking, and sensor devices and applications.

A Brief Overview of China's ETS Pilots - Deconstruction and Assessment of Guangdong's Greenhouse Gas Emission Trading... A Brief Overview of China's ETS Pilots - Deconstruction and Assessment of Guangdong's Greenhouse Gas Emission Trading Mechanism (Hardcover, 1st ed. 2019)
Daiqing Zhao, Wenjun Wang, Zhigang Luo
R2,955 Discovery Miles 29 550 Ships in 10 - 15 working days

This book systematically introduces readers to the framework of China's ETS pilots, exploring their design and operating process, the current state of the carbon market, and various barriers encountered. To do so, it deconstructs the Guangdong ETS, which is the largest and most representative of China's seven ETS pilots. The book subsequently describes and evaluates all seven pilots in terms of their efficiency, macro and micro effects, the method involved in the DEA model, the CGE model, and cost-benefit analysis. In turn, in the assessment section it demonstrates how some ETS pilots have failed to control carbon emissions due to inordinately high emissions quotas issued by the local government etc. Further, it argues that ETS should focus on those industries with large emissions and high mitigating potential for the time being, and then gradually expand the scale of its coverage. As China's national ETS is slated for launch on the basis of the lessons learned from the ETS pilots, the book offers a timely and valuable resource for all those who want to understand and forecast the development of China's ETS. It includes a wealth of descriptions and explanations of Chinese government policies involving carbon emissions control, making it a unique resource.

Electric Potential in Toroidal Plasmas (Hardcover, 1st ed. 2019): A.V. Mel'nikov Electric Potential in Toroidal Plasmas (Hardcover, 1st ed. 2019)
A.V. Mel'nikov
R3,451 Discovery Miles 34 510 Ships in 10 - 15 working days

This work introduces heavy ion beam probe diagnostics and presents an overview of its applications. The heavy ion beam probe is a unique tool for the measurement of potential in the plasma core in order to understand the role of the electric field in plasma confinement, including the mechanism of transition from low to high confinement regimes (L-H transition). This allows measurement of the steady-state profile of the plasma potential, and its use has been extended to include the measurement of quasi-monochromatic and broadband oscillating components, the turbulent-particle flux and oscillations of the electron density and poloidal magnetic field. Special emphasis is placed on the study of Geodesic Acoustic Modes and Alfven Eigenmodes excited by energetic particles with experimental data sets. These experimental studies help to understand the link between broadband turbulent physics and quasi-coherent oscillations in devices with a rather different magnetic configuration. The book also compares spontaneous and biased transitions from low to high confinement regimes on both classes of closed magnetic traps (tokamak and stellarator) and highlights the common features in the behavior of electric potential and turbulence of magnetized plasmas. A valuable resource for physicists, postgraduates and students specializing in plasma physics and controlled fusion.

Nanoenergy - Nanotechnology Applied for Energy Production (Hardcover, 2nd ed. 2018): Flavio L Souza, Edson R Leite Nanoenergy - Nanotechnology Applied for Energy Production (Hardcover, 2nd ed. 2018)
Flavio L Souza, Edson R Leite
R4,918 Discovery Miles 49 180 Ships in 12 - 17 working days

This book discuss the recent advances and future trends of nanoscience in solar energy conversion and storage. This second edition revisits and updates all the previous book chapters, adding the latest advances in the field of Nanoenergy. Four new chapters are included on the principles and fundamentals of artificial photosynthesis using metal transition semiconductors, perovskite solar cells, hydrogen storage and neutralization batteries. More fundamental aspects can be found in this book, increasing the comparison between theory-experimental achievements and latest developments in commercial devices.

Applications of High Temperature Superconductors to Electric Power Equipment (Hardcover, New): S.S. Kalsi Applications of High Temperature Superconductors to Electric Power Equipment (Hardcover, New)
S.S. Kalsi
R3,226 Discovery Miles 32 260 Ships in 12 - 17 working days

The only one-stop reference to design, analysis, and manufacturing concepts for power devices utilizing HTS.

High temperature superconductors (HTS) have been used for building many devices for electric grids worldwide and for large ship propulsion motors for the U.S. Navy. And yet, there has been no single source discussing theory and design issues relating to power applications of HTS--until now. This book provides design and analysis for various devices and includes examples of devices built over the last decade.

Starting with a complete overview of HTS, the subsequent chapters are dedicated to specific devices: cooling and thermal insulation systems; rotating AC and DC machines; transformers; fault current limiters; power cables; and Maglev transport. As applicable, each chapter provides a history of the device, principles, configuration, design and design challenges, prototypes, and manufacturing issues, with each ending with a summary of the material covered. The design analysis and design examples provide critical insight for readers to successfully design their own devices. Original equipment manufacturer (OEM) designers, industry and utilities users, universities and defense services research groups, and senior/postgraduate engineering students and instructors will rely on this resource.

"HTS technology reduces electric losses and increases the efficiency of power equipment. This book by Swarn Kalsi, a leading expert on the HTS subject, provides a survey of the HTS technology and the design rules, performance analyses, and manufacturing concepts for power application-related devices. It compares conventional and HTS technology approaches for device design and provides significant examples of devices utilizing the HTS technology today. The book is useful for a broad spectrum of professionals worldwide: students, teaching staff, and OEM designers as well as users in industry and electric utilities."
--Professor Dr. Rolf Hellinger, Research and Technologies Corporate Technology, Siemens AG

Computer-generated Holographic Matched Filters (Hardcover): Steven Butler Computer-generated Holographic Matched Filters (Hardcover)
Steven Butler
R2,306 Discovery Miles 23 060 Ships in 10 - 15 working days
Biomass, Biorefineries and Bioeconomy (Hardcover): Mohamed Samer Biomass, Biorefineries and Bioeconomy (Hardcover)
Mohamed Samer
R3,451 Discovery Miles 34 510 Ships in 10 - 15 working days
m-Mode SVPWM Technique for Power Converters (Hardcover, 1st ed. 2019): Bo Zhang, Dongyuan Qiu m-Mode SVPWM Technique for Power Converters (Hardcover, 1st ed. 2019)
Bo Zhang, Dongyuan Qiu
R3,436 Discovery Miles 34 360 Ships in 10 - 15 working days

This book presents a novel control method for power converters, referred to as m-mode control. It provides an overview of traditional control methods for inverters - e.g. PWM and SVPWM - and the theory of the m-mode control method, while also discussing and applying m-mode control on various types of converters (including three-phase, nine-switch, five-leg and multi-level inverters, PWM rectifiers and modular multi-level converters). The book provides readers with sufficient background and understanding to delve deeper into the topic of SVPWM control. It is also a valuable guide for engineers and researchers whose work involves power converter control.

Explosions in Underground Coal Mines - Risk Assessment and Control (Hardcover, 1st ed. 2018): Jianwei Cheng Explosions in Underground Coal Mines - Risk Assessment and Control (Hardcover, 1st ed. 2018)
Jianwei Cheng
R2,939 Discovery Miles 29 390 Ships in 10 - 15 working days

This book addresses the hazard of gas explosions in sealed underground coal mines, and how the risk of explosion can be assessed, modeled, and mitigated. With this text, coal mine operators and managers will be able to identify the risks that lead to underground mine gas explosions, and implement practical strategies to optimize mining safety for workers. In six chapters, the book offers a framework for understanding the sealed coal mine atmosphere, the safety characteristics that are currently in place, and the guidelines to be followed by engineers to improve upon these characteristics. The first part of the book describes the importance and characteristics of underground gas mine explosions in a historical context with data showing the high number of fatalities from explosion incidents, and how risk has been mitigated in the past. Chapters also detail mathematical models and explosibility diagrams for determining and understanding the risk factors involved in mine explosions. Readers will also learn about safety operations, and assessments for the sealed mine atmosphere. With descriptions of chapter case studies, mining engineers and researchers will learn how to apply safety measures in underground coal mines to improve mining atmospheres and save lives.

Renewable Energy Powered Desalination Handbook - Application and Thermodynamics (Paperback): Gnaneswar Gnaneswar Gude Renewable Energy Powered Desalination Handbook - Application and Thermodynamics (Paperback)
Gnaneswar Gnaneswar Gude
R4,586 R4,164 Discovery Miles 41 640 Save R422 (9%) Ships in 12 - 17 working days

Renewable Energy Powered Desalination Handbook: Applications and Thermodynamics offers a practical handbook on the use of renewable technologies to produce freshwater using sustainable methods. Sections cover the different renewable technologies currently used in the field, including solar, wind, geothermal and nuclear desalination. This coverage is followed by an equally important clear and rigorous discussion of energy recovery and the thermodynamics of desalination processes. While seawater desalination can provide a climate-independent source of drinking water, the process is energy-intensive and environmentally damaging. This book provides readers with the latest methods, processes, and technologies available for utilizing renewable energy applications as a valuable technology. Desalination based on the use of renewable energy sources can provide a sustainable way to produce fresh water. It is expected to become economically attractive as the costs of renewable technologies continue to decline and the prices of fossil fuels continue to increase.

Progress in Optics, Volume 63 (Hardcover): Taco Visser Progress in Optics, Volume 63 (Hardcover)
Taco Visser
R4,983 Discovery Miles 49 830 Ships in 12 - 17 working days

Progress in Optics, Volume 63 is the latest release in a series that presents an overview of the state-of-the-art in optics research. In this update, readers will find timely chapters on measuring polarization states, quantum measurement, optical trapping, spatial/spectral correspondence for mono/poly chromatic light diffraction, and photonic fractional signal processing, amongst other timely topics.

Energy and Environment - Select Proceedings of ICWEES-2016 (Hardcover, 1st ed. 2018): Vijay P. Singh, Shalini Yadav, Ram... Energy and Environment - Select Proceedings of ICWEES-2016 (Hardcover, 1st ed. 2018)
Vijay P. Singh, Shalini Yadav, Ram Narayan Yadava
R4,850 Discovery Miles 48 500 Ships in 12 - 17 working days

This book comprising seven parts is organized under two sections. The first section deals with environment containing four parts, whereas the second section, containing three parts, is on energy. The first part deals with some aspects of hydrologic impacts of global warming and anthropogenic changes. Part II is on bio-environment and discusses plants, biomass, and bacterial species. Part III focuses on chemical environment. Section one is concluded with Part IV on social environment. Section two starts out with Part V on solar energy. Hydropower is discussed in Part VI. The concluding Part VII deals with biogas. The book will be of interest to researchers and practitioners in the field of water resources, hydrology, environmental resources, agricultural engineering, watershed management, earth sciences, as well as those engaged in natural resources planning and management. Graduate students and those wishing to conduct further research in water and environment and their development and management may find the book to be of value.

Energy from Microalgae (Hardcover, 1st ed. 2018): Eduardo Jacob-Lopes, Leila Queiroz Zepka, Maria Isabel Queiroz Energy from Microalgae (Hardcover, 1st ed. 2018)
Eduardo Jacob-Lopes, Leila Queiroz Zepka, Maria Isabel Queiroz
R3,723 Discovery Miles 37 230 Ships in 10 - 15 working days

This book presents an authoritative and comprehensive overview of the production and use of microalgal biomass and bioproducts for energy generation. It also offers extensive information on engineering approaches to energy production, such as process integration and process intensification in harnessing energy from microalgae. Issues related to the environment, food, chemicals and energy supply pose serious threats to nations' success and stability. The challenge to provide for a rapidly growing global population has made it imperative to find new technological routes to increase the production of consumables while also bearing in mind the biosphere's ability to regenerate resources. Microbial biomass is a bioresource that provides effective solutions to these challenges. Divided into eight parts, the book explores microalgal production systems, life cycle assessment and the bio-economy of biofuels from microalgae, process integration and process intensification applied to microalgal biofuels production. In addition, it discusses the main fuel products obtained from microalgae, summarizing a range of useful energy products derived from algae-based systems, and outlines future developments. Given the book's breadth of coverage and extensive bibliography, it offers an essential resource for researchers and industry professionals working in renewable energy.

Control of Induction Motors (Hardcover): Andrzej M. Trzynadlowski Control of Induction Motors (Hardcover)
Andrzej M. Trzynadlowski
R2,949 Discovery Miles 29 490 Ships in 12 - 17 working days

This book is a comprehensive reference source for practicing engineers and students specializing in electric power engineering and industrial electronics. It will illustrate the state of the art in induction motors. Beginning with characteristics and basic dynamic models of induction motors, and progressing to low- and high- performance drive systems. The book will be rich in useful information, without an excessive mathematical burden. Computer simulations resulting in mock oscillograms of physical quantities are used for illustration of basic control concepts.
The content of this book is divided into three basic parts: 1) control-oriented description of induction motors, 2) control methods, and systems, 3) control means. An induction motor is presented as an electromechanical power converter, and basic relations between the electrical, magnetic and mechanical quantities in the motor will be explained. Control methods and systems will be classified according to the controlled variables(torque, speed, flux), actuating variables(voltage, current), and dynamic performance (uncontrolled, low-performance, and high-performance). An overview of power electronic converters and information processing equipment used in the modern induction motor drives is included. Such systematic approach will give the readers a comprehensive overview of the field of induction motor control.

Free Delivery
Pinterest Twitter Facebook Google+
You may like...
Encyclopedia of Energy Storage
Luisa F. Cabeza Hardcover R58,100 Discovery Miles 581 000
Eskom - Power, Politics And The (Post…
Faeeza Ballim Paperback R280 R219 Discovery Miles 2 190
Materials for Sustainable Energy, Volume…
Rudi van Eldik, Wojciech Macyk Hardcover R6,114 Discovery Miles 61 140
Encyclopedia of Nuclear Energy
Ehud Greenspan Hardcover R69,070 Discovery Miles 690 700
Advances in Bioenergy, Volume 3
Yebo Li, Xumeng Ge Paperback R4,344 Discovery Miles 43 440
Clean Energy and Resources Recovery…
Vinay Kumar Tyagi, Kaoutar Aboudi Paperback R3,710 Discovery Miles 37 100
Science, Technology, and Innovation for…
Ademola A. Adenle, Marian R. Chertow, … Hardcover R3,172 Discovery Miles 31 720
Education and Training for the Oil and…
Phil Andrews, Jim Playfoot Hardcover R2,171 Discovery Miles 21 710
Materials Ageing and Degradation in…
K.L. Murty Hardcover R4,558 Discovery Miles 45 580
Single Cell Oils - Microbial and Algal…
Zvi Cohen, Colin Ratledge Paperback R2,782 Discovery Miles 27 820

 

Partners