Author: Ahmed Belasri
Publisher: Springer Nature
ISBN: 9811554447
Category : Technology & Engineering
Languages : en
Pages : 659
Book Description
This book highlights peer reviewed articles from the 1st International Conference on Renewable Energy and Energy Conversion, ICREEC 2019, held at Oran in Algeria. It presents recent advances, brings together researchers and professionals in the area and presents a platform to exchange ideas and establish opportunities for a sustainable future. Topics covered in this proceedings, but not limited to, are photovoltaic systems, bioenergy, laser and plasma technology, fluid and flow for energy, software for energy and impact of energy on the environment.
ICREEC 2019
Author: Ahmed Belasri
Publisher: Springer Nature
ISBN: 9811554447
Category : Technology & Engineering
Languages : en
Pages : 659
Book Description
This book highlights peer reviewed articles from the 1st International Conference on Renewable Energy and Energy Conversion, ICREEC 2019, held at Oran in Algeria. It presents recent advances, brings together researchers and professionals in the area and presents a platform to exchange ideas and establish opportunities for a sustainable future. Topics covered in this proceedings, but not limited to, are photovoltaic systems, bioenergy, laser and plasma technology, fluid and flow for energy, software for energy and impact of energy on the environment.
Publisher: Springer Nature
ISBN: 9811554447
Category : Technology & Engineering
Languages : en
Pages : 659
Book Description
This book highlights peer reviewed articles from the 1st International Conference on Renewable Energy and Energy Conversion, ICREEC 2019, held at Oran in Algeria. It presents recent advances, brings together researchers and professionals in the area and presents a platform to exchange ideas and establish opportunities for a sustainable future. Topics covered in this proceedings, but not limited to, are photovoltaic systems, bioenergy, laser and plasma technology, fluid and flow for energy, software for energy and impact of energy on the environment.
Introduction to Modeling and Control of Internal Combustion Engine Systems
Author: Lino Guzzella
Publisher: Springer Science & Business Media
ISBN: 3662080036
Category : Technology & Engineering
Languages : en
Pages : 303
Book Description
Internal combustion engines still have a potential for substantial improvements, particularly with regard to fuel efficiency and environmental compatibility. These goals can be achieved with help of control systems. Modeling and Control of Internal Combustion Engines (ICE) addresses these issues by offering an introduction to cost-effective model-based control system design for ICE. The primary emphasis is put on the ICE and its auxiliary devices. Mathematical models for these processes are developed in the text and selected feedforward and feedback control problems are discussed. The appendix contains a summary of the most important controller analysis and design methods, and a case study that analyzes a simplified idle-speed control problem. The book is written for students interested in the design of classical and novel ICE control systems.
Publisher: Springer Science & Business Media
ISBN: 3662080036
Category : Technology & Engineering
Languages : en
Pages : 303
Book Description
Internal combustion engines still have a potential for substantial improvements, particularly with regard to fuel efficiency and environmental compatibility. These goals can be achieved with help of control systems. Modeling and Control of Internal Combustion Engines (ICE) addresses these issues by offering an introduction to cost-effective model-based control system design for ICE. The primary emphasis is put on the ICE and its auxiliary devices. Mathematical models for these processes are developed in the text and selected feedforward and feedback control problems are discussed. The appendix contains a summary of the most important controller analysis and design methods, and a case study that analyzes a simplified idle-speed control problem. The book is written for students interested in the design of classical and novel ICE control systems.
Large-Scale Inverse Problems and Quantification of Uncertainty
Author: Lorenz Biegler
Publisher: John Wiley & Sons
ISBN: 1119957583
Category : Mathematics
Languages : en
Pages : 403
Book Description
This book focuses on computational methods for large-scale statistical inverse problems and provides an introduction to statistical Bayesian and frequentist methodologies. Recent research advances for approximation methods are discussed, along with Kalman filtering methods and optimization-based approaches to solving inverse problems. The aim is to cross-fertilize the perspectives of researchers in the areas of data assimilation, statistics, large-scale optimization, applied and computational mathematics, high performance computing, and cutting-edge applications. The solution to large-scale inverse problems critically depends on methods to reduce computational cost. Recent research approaches tackle this challenge in a variety of different ways. Many of the computational frameworks highlighted in this book build upon state-of-the-art methods for simulation of the forward problem, such as, fast Partial Differential Equation (PDE) solvers, reduced-order models and emulators of the forward problem, stochastic spectral approximations, and ensemble-based approximations, as well as exploiting the machinery for large-scale deterministic optimization through adjoint and other sensitivity analysis methods. Key Features: Brings together the perspectives of researchers in areas of inverse problems and data assimilation. Assesses the current state-of-the-art and identify needs and opportunities for future research. Focuses on the computational methods used to analyze and simulate inverse problems. Written by leading experts of inverse problems and uncertainty quantification. Graduate students and researchers working in statistics, mathematics and engineering will benefit from this book.
Publisher: John Wiley & Sons
ISBN: 1119957583
Category : Mathematics
Languages : en
Pages : 403
Book Description
This book focuses on computational methods for large-scale statistical inverse problems and provides an introduction to statistical Bayesian and frequentist methodologies. Recent research advances for approximation methods are discussed, along with Kalman filtering methods and optimization-based approaches to solving inverse problems. The aim is to cross-fertilize the perspectives of researchers in the areas of data assimilation, statistics, large-scale optimization, applied and computational mathematics, high performance computing, and cutting-edge applications. The solution to large-scale inverse problems critically depends on methods to reduce computational cost. Recent research approaches tackle this challenge in a variety of different ways. Many of the computational frameworks highlighted in this book build upon state-of-the-art methods for simulation of the forward problem, such as, fast Partial Differential Equation (PDE) solvers, reduced-order models and emulators of the forward problem, stochastic spectral approximations, and ensemble-based approximations, as well as exploiting the machinery for large-scale deterministic optimization through adjoint and other sensitivity analysis methods. Key Features: Brings together the perspectives of researchers in areas of inverse problems and data assimilation. Assesses the current state-of-the-art and identify needs and opportunities for future research. Focuses on the computational methods used to analyze and simulate inverse problems. Written by leading experts of inverse problems and uncertainty quantification. Graduate students and researchers working in statistics, mathematics and engineering will benefit from this book.
Engines and Powertrains
Author: Ronald K Jurgen
Publisher: SAE International
ISBN: 0768057191
Category : Technology & Engineering
Languages : en
Pages : 147
Book Description
With production and planning for new electric vehicles gaining momentum worldwide, this book – the third in a series of five volumes on this subject – provides engineers and researchers with perspectives on the most current and innovative developments regarding electric and hybrid-electric vehicle technology, design considerations, and components. This book features 13 SAE technical papers, published from 2008 through 2010, that provide an overview of research on electric vehicle engines and powertrains. Topics include: Hybrid-electric vehicle transmissions and propulsion systems The development of a new 1.8-liter engine for hybrid vehicles Vehicle system control software validation The impact of hybrid-electric powertrains on chassis systems and vehicle dynamics High-torque density motors, and interior permanent magnet synchronous motors
Publisher: SAE International
ISBN: 0768057191
Category : Technology & Engineering
Languages : en
Pages : 147
Book Description
With production and planning for new electric vehicles gaining momentum worldwide, this book – the third in a series of five volumes on this subject – provides engineers and researchers with perspectives on the most current and innovative developments regarding electric and hybrid-electric vehicle technology, design considerations, and components. This book features 13 SAE technical papers, published from 2008 through 2010, that provide an overview of research on electric vehicle engines and powertrains. Topics include: Hybrid-electric vehicle transmissions and propulsion systems The development of a new 1.8-liter engine for hybrid vehicles Vehicle system control software validation The impact of hybrid-electric powertrains on chassis systems and vehicle dynamics High-torque density motors, and interior permanent magnet synchronous motors
Noise of Polyphase Electric Motors
Author: Jacek F. Gieras
Publisher: CRC Press
ISBN: 1420027735
Category : Technology & Engineering
Languages : en
Pages : 392
Book Description
Controlling the level of noise in electrical motors is critical to overall system performance. However, predicting noise of an electrical motor is more difficult and less accurate than for other characteristics such as torque-speed. Recent advances have produced powerful computational methods for noise prediction, and Noise of Polyphase Electric Motors is the first book to collect these advances in a single source. It is also the first to include noise prediction for permanent magnet (PM) synchronous motors. Complete coverage of all aspects of electromagnetic, structural, and vibro-acoustic noise makes this a uniquely comprehensive reference. The authors begin with the basic principles of noise generation and radiation, magnetic field and radial forces, torque pulsations, acoustic calculations, as well as noise and vibration of mechanical and acoustic origin. Moving to applications, the book examines in detail stator system vibration analysis including the use of finite element method (FEM) modal analysis; FEM for radial pressure and structural modeling; boundary element methods (BEM) for acoustic radiation; statistical energy analysis (SEA); instrumentation including technologies, procedures, and standards; and both passive and active methods for control of noise and vibration. Noise of Polyphase Electric Motors gathers the fundamental concepts along with all of the analytical, numerical, and statistical methods into a unified reference. It supplies all of the tools necessary to improve the noise performance of electrical motors at the design stage.
Publisher: CRC Press
ISBN: 1420027735
Category : Technology & Engineering
Languages : en
Pages : 392
Book Description
Controlling the level of noise in electrical motors is critical to overall system performance. However, predicting noise of an electrical motor is more difficult and less accurate than for other characteristics such as torque-speed. Recent advances have produced powerful computational methods for noise prediction, and Noise of Polyphase Electric Motors is the first book to collect these advances in a single source. It is also the first to include noise prediction for permanent magnet (PM) synchronous motors. Complete coverage of all aspects of electromagnetic, structural, and vibro-acoustic noise makes this a uniquely comprehensive reference. The authors begin with the basic principles of noise generation and radiation, magnetic field and radial forces, torque pulsations, acoustic calculations, as well as noise and vibration of mechanical and acoustic origin. Moving to applications, the book examines in detail stator system vibration analysis including the use of finite element method (FEM) modal analysis; FEM for radial pressure and structural modeling; boundary element methods (BEM) for acoustic radiation; statistical energy analysis (SEA); instrumentation including technologies, procedures, and standards; and both passive and active methods for control of noise and vibration. Noise of Polyphase Electric Motors gathers the fundamental concepts along with all of the analytical, numerical, and statistical methods into a unified reference. It supplies all of the tools necessary to improve the noise performance of electrical motors at the design stage.
Hybrid Vehicles
Author: BADIN François
Publisher: Editions TECHNIP
ISBN: 271080994X
Category : Reference
Languages : en
Pages : 526
Book Description
The fast growth in world population and the associated energy requirements, the announced depletion of fossil fuel resources, the continuing rise in greenhouse gas (GHG) emissions with the induced climatic changes represent some of the major challenges to be taken up in the coming years and decades. Hybridization therefore typically represents a transition technology which can significantly improve the energy and environmental performance of current vehicles, without radically changing their use typologies, while opening the way to new propulsion modes for the longer term. It is nevertheless a complex subject requiring a multidisciplinary approach. This book, which is intended to be exhaustive, considers the vehicle, its components, their association and their control, as well as the global balances determined over the vehicle lifetime. It starts with a general presentation of the various conditions of use of vehicles, to give readers an understanding of the stakes related to the development of hybrid vehicles and the methods used to compare the performance of the various solutions. The principles and the various types of internal combustion engine and electrical drives, onboard energy storage systems, principles, architectures, specific components and operation of hybrid drivetrains, as well as the energy management in these vehicles, are developed. A global analysis of the various drivetrains life cycle assessment (LCA), total costs and availability of sensitive materials is also provided. This book is intended for everyone involved in the design, manufacture and implementation of hybrid drive vehicles and their components. It will also be of interest to students, teachers and researchers wishing to acquire or further their knowledge in all fields impacted by drivetrain electrification. More globally, after consulting this book, readers will be in a position to evaluate the technologies related to the concept of drivetrain hybridization, their implementation, balances and generalization conditions. This book is available in French Under the title "Véhicules hybrides". Contents : 1. Vehicle use. 2. Internal combustion engines. 3. Electric drivetrain. 4. On-board energy storage systems. 5. Hybridization. 6. Control of hybrid vehicles. 7. Comparative study of hybrid vehicles: greenhouse gas emissions, energy consumption, and cost. Appendixes.
Publisher: Editions TECHNIP
ISBN: 271080994X
Category : Reference
Languages : en
Pages : 526
Book Description
The fast growth in world population and the associated energy requirements, the announced depletion of fossil fuel resources, the continuing rise in greenhouse gas (GHG) emissions with the induced climatic changes represent some of the major challenges to be taken up in the coming years and decades. Hybridization therefore typically represents a transition technology which can significantly improve the energy and environmental performance of current vehicles, without radically changing their use typologies, while opening the way to new propulsion modes for the longer term. It is nevertheless a complex subject requiring a multidisciplinary approach. This book, which is intended to be exhaustive, considers the vehicle, its components, their association and their control, as well as the global balances determined over the vehicle lifetime. It starts with a general presentation of the various conditions of use of vehicles, to give readers an understanding of the stakes related to the development of hybrid vehicles and the methods used to compare the performance of the various solutions. The principles and the various types of internal combustion engine and electrical drives, onboard energy storage systems, principles, architectures, specific components and operation of hybrid drivetrains, as well as the energy management in these vehicles, are developed. A global analysis of the various drivetrains life cycle assessment (LCA), total costs and availability of sensitive materials is also provided. This book is intended for everyone involved in the design, manufacture and implementation of hybrid drive vehicles and their components. It will also be of interest to students, teachers and researchers wishing to acquire or further their knowledge in all fields impacted by drivetrain electrification. More globally, after consulting this book, readers will be in a position to evaluate the technologies related to the concept of drivetrain hybridization, their implementation, balances and generalization conditions. This book is available in French Under the title "Véhicules hybrides". Contents : 1. Vehicle use. 2. Internal combustion engines. 3. Electric drivetrain. 4. On-board energy storage systems. 5. Hybridization. 6. Control of hybrid vehicles. 7. Comparative study of hybrid vehicles: greenhouse gas emissions, energy consumption, and cost. Appendixes.
Optimization Methods and Applications
Author: Xiao-qi Yang
Publisher: Springer Science & Business Media
ISBN: 147573333X
Category : Computers
Languages : en
Pages : 439
Book Description
This edited book is dedicated to Professor N. U. Ahmed, a leading scholar and a renowned researcher in optimal control and optimization on the occasion of his retirement from the Department of Electrical Engineering at University of Ottawa in 1999. The contributions of this volume are in the areas of optimal control, non linear optimization and optimization applications. They are mainly the im proved and expanded versions of the papers selected from those presented in two special sessions of two international conferences. The first special session is Optimization Methods, which was organized by K. L. Teo and X. Q. Yang for the International Conference on Optimization and Variational Inequality, the City University of Hong Kong, Hong Kong, 1998. The other one is Optimal Control, which was organized byK. ~Teo and L. Caccetta for the Dynamic Control Congress, Ottawa, 1999. This volume is divided into three parts: Optimal Control; Optimization Methods; and Applications. The Optimal Control part is concerned with com putational methods, modeling and nonlinear systems. Three computational methods for solving optimal control problems are presented: (i) a regularization method for computing ill-conditioned optimal control problems, (ii) penalty function methods that appropriately handle final state equality constraints, and (iii) a multilevel optimization approach for the numerical solution of opti mal control problems. In the fourth paper, the worst-case optimal regulation involving linear time varying systems is formulated as a minimax optimal con trol problem.
Publisher: Springer Science & Business Media
ISBN: 147573333X
Category : Computers
Languages : en
Pages : 439
Book Description
This edited book is dedicated to Professor N. U. Ahmed, a leading scholar and a renowned researcher in optimal control and optimization on the occasion of his retirement from the Department of Electrical Engineering at University of Ottawa in 1999. The contributions of this volume are in the areas of optimal control, non linear optimization and optimization applications. They are mainly the im proved and expanded versions of the papers selected from those presented in two special sessions of two international conferences. The first special session is Optimization Methods, which was organized by K. L. Teo and X. Q. Yang for the International Conference on Optimization and Variational Inequality, the City University of Hong Kong, Hong Kong, 1998. The other one is Optimal Control, which was organized byK. ~Teo and L. Caccetta for the Dynamic Control Congress, Ottawa, 1999. This volume is divided into three parts: Optimal Control; Optimization Methods; and Applications. The Optimal Control part is concerned with com putational methods, modeling and nonlinear systems. Three computational methods for solving optimal control problems are presented: (i) a regularization method for computing ill-conditioned optimal control problems, (ii) penalty function methods that appropriately handle final state equality constraints, and (iii) a multilevel optimization approach for the numerical solution of opti mal control problems. In the fourth paper, the worst-case optimal regulation involving linear time varying systems is formulated as a minimax optimal con trol problem.
Distributed Propulsion Technology
Author: Amir S. Gohardani
Publisher: Nova Science Publishers
ISBN: 9781629485881
Category : Airplanes
Languages : en
Pages : 0
Book Description
Distributed propulsion technology is one of the revolutionary candidates for future aircraft propulsion. In this book, which serves as the very first reference book on distributed propulsion technology, the potential role of distributed propulsion technology in future aviation is investigated. Following a historical journey that revisits distributed propulsion technology in unmanned air vehicles, commercial aircrafts, and military aircrafts, features of this specific technology are highlighted in synergy with an electric aircraft concept and a first-of-its-kind comparison between commercial and military aircrafts employing distributed propulsion arrangements. In light of propulsionairframe integration and complementary technologies, such as boundary layer ingestion, thrust vectoring and circulation control, transpired opportunities and challenges are addressed in addition to a number of identified research directions proposed for future aircrafts. Moreover, a diverse set of distributed propulsion arrangements are considered. These include: small engines, gas-driven multi-fan architectures, turboelectric systems featuring superconductive and non-superconducting electrical machine technology, and electromagnetic fans. This book features contributions by the National Aeronautics and Space Administration (NASA) and the United States Air Force (USAF), and includes the first proposed official definition for distributed propulsion technology in subsonic fixed wing aircrafts.
Publisher: Nova Science Publishers
ISBN: 9781629485881
Category : Airplanes
Languages : en
Pages : 0
Book Description
Distributed propulsion technology is one of the revolutionary candidates for future aircraft propulsion. In this book, which serves as the very first reference book on distributed propulsion technology, the potential role of distributed propulsion technology in future aviation is investigated. Following a historical journey that revisits distributed propulsion technology in unmanned air vehicles, commercial aircrafts, and military aircrafts, features of this specific technology are highlighted in synergy with an electric aircraft concept and a first-of-its-kind comparison between commercial and military aircrafts employing distributed propulsion arrangements. In light of propulsionairframe integration and complementary technologies, such as boundary layer ingestion, thrust vectoring and circulation control, transpired opportunities and challenges are addressed in addition to a number of identified research directions proposed for future aircrafts. Moreover, a diverse set of distributed propulsion arrangements are considered. These include: small engines, gas-driven multi-fan architectures, turboelectric systems featuring superconductive and non-superconducting electrical machine technology, and electromagnetic fans. This book features contributions by the National Aeronautics and Space Administration (NASA) and the United States Air Force (USAF), and includes the first proposed official definition for distributed propulsion technology in subsonic fixed wing aircrafts.
"All it Is, It's a Carnival"
Author: Mária Németh Lenke
Publisher:
ISBN:
Category : American drama
Languages : en
Pages : 164
Book Description
Publisher:
ISBN:
Category : American drama
Languages : en
Pages : 164
Book Description
Electrochemical Components
Author: Marie-Cécile Pera
Publisher: John Wiley & Sons
ISBN: 9781848214019
Category : Technology & Engineering
Languages : en
Pages : 0
Book Description
This book focuses on the methods of storage commonly used in hybrid systems. After an introductory chapter reviewing the basics of electrochemistry, Chapter 2 is given over to the storage of electricity in the form of hydrogen. Once hydrogen has been made, we have to be able to convert it back into electricity on demand. This can be done with another energy converter: a fuel cell, the subject of Chapter 3. Such a system is unable to deliver significant dynamics in terms of storage and release of electricity and needs to be supplemented with another solution: a detailed study of supercapacitors is provided in Chapter 4.While the storage systems touched upon in the previous three chapters (hydrogen batteries and supercapacitors) both exhibit advantageous characteristics, at present they are still relatively costly. Thus, the days of the electrochemical accumulator by no means appear to be numbered just yet. This will therefore be the topic of Chapter 5. Finally, on the basis of the elements laid down in the previous chapters, Chapter 6 will focus on electrical hybridization of these storage systems, with a view to enhancing the performance (in terms of energy, lifetime, cost, etc.) of the newly formed system. Aimed at an audience of researchers, industrialists, academics, teachers and students, many exercises, along with corrected solutions, are provided throughout the book. Contents 1. Basic Concepts of Electrochemistry used in Electrical Engineering. 2. Water Electrolyzers. 3. Fuel Cells. 4. Electrical Energy Storage by Supercapacitors. 5. Electrochemical Accumulators. 6. Hybrid Electrical System. About the Authors Marie-Cécile Péra is a Full Professor at the University of Franche-Comte in France and Deputy Director of the FEMTO-ST Institute (CNRS). Her research activities include modeling, control and diagnosis of electric power generation systems (fuel cells – PEMFC and SOFC, supercapacities, batteries) for transportation and stationary applications. She has contributed to more than 180 articles in international journals and conferences. Daniel Hissel is Full Professor at the University of Franche-Comte in France and Director of the Fuel Cell Lab Research Federation (CNRS). He also leads a research team devoted to hybrid electrical systems in the FEMTO-ST Institute (CNRS). He has published more than 250 research papers on modeling, control, diagnostics and prognostics of hybrid electrical systems. Hamid Gualous is Full Professor at the University of Caen Lower Normandy in France and director of the LUSAC laboratory. His current research interests include power electronics, electric energy storage, power and energy systems and energy management. Christophe Turpin is Full Researcher at the CNRS (French National Center for Scientific Research). He is responsible for hydrogen activities within the Laboratory LAPLACE, Toulouse, France. His research activities include the characterization and modeling of fuel cells and electrolyzers, the state of health of these components, and their hybridization with other electrochemical components (ultracapacitors, batteries) within optimized energy systems for stationary and aeronautical applications.
Publisher: John Wiley & Sons
ISBN: 9781848214019
Category : Technology & Engineering
Languages : en
Pages : 0
Book Description
This book focuses on the methods of storage commonly used in hybrid systems. After an introductory chapter reviewing the basics of electrochemistry, Chapter 2 is given over to the storage of electricity in the form of hydrogen. Once hydrogen has been made, we have to be able to convert it back into electricity on demand. This can be done with another energy converter: a fuel cell, the subject of Chapter 3. Such a system is unable to deliver significant dynamics in terms of storage and release of electricity and needs to be supplemented with another solution: a detailed study of supercapacitors is provided in Chapter 4.While the storage systems touched upon in the previous three chapters (hydrogen batteries and supercapacitors) both exhibit advantageous characteristics, at present they are still relatively costly. Thus, the days of the electrochemical accumulator by no means appear to be numbered just yet. This will therefore be the topic of Chapter 5. Finally, on the basis of the elements laid down in the previous chapters, Chapter 6 will focus on electrical hybridization of these storage systems, with a view to enhancing the performance (in terms of energy, lifetime, cost, etc.) of the newly formed system. Aimed at an audience of researchers, industrialists, academics, teachers and students, many exercises, along with corrected solutions, are provided throughout the book. Contents 1. Basic Concepts of Electrochemistry used in Electrical Engineering. 2. Water Electrolyzers. 3. Fuel Cells. 4. Electrical Energy Storage by Supercapacitors. 5. Electrochemical Accumulators. 6. Hybrid Electrical System. About the Authors Marie-Cécile Péra is a Full Professor at the University of Franche-Comte in France and Deputy Director of the FEMTO-ST Institute (CNRS). Her research activities include modeling, control and diagnosis of electric power generation systems (fuel cells – PEMFC and SOFC, supercapacities, batteries) for transportation and stationary applications. She has contributed to more than 180 articles in international journals and conferences. Daniel Hissel is Full Professor at the University of Franche-Comte in France and Director of the Fuel Cell Lab Research Federation (CNRS). He also leads a research team devoted to hybrid electrical systems in the FEMTO-ST Institute (CNRS). He has published more than 250 research papers on modeling, control, diagnostics and prognostics of hybrid electrical systems. Hamid Gualous is Full Professor at the University of Caen Lower Normandy in France and director of the LUSAC laboratory. His current research interests include power electronics, electric energy storage, power and energy systems and energy management. Christophe Turpin is Full Researcher at the CNRS (French National Center for Scientific Research). He is responsible for hydrogen activities within the Laboratory LAPLACE, Toulouse, France. His research activities include the characterization and modeling of fuel cells and electrolyzers, the state of health of these components, and their hybridization with other electrochemical components (ultracapacitors, batteries) within optimized energy systems for stationary and aeronautical applications.