Author: Hamida Hallil
Publisher: John Wiley & Sons
ISBN: 1119587344
Category : Technology & Engineering
Languages : en
Pages : 240
Book Description
Provides an introduction to the topic of smart chemical sensors, along with an overview of the state of the art based on potential applications This book presents a comprehensive overview of chemical sensors, ranging from the choice of material to sensor validation, modeling, simulation, and manufacturing. It discusses the process of data collection by intelligent techniques such as deep learning, multivariate analysis, and others. It also incorporates different types of smart chemical sensors and discusses each under a common set of sub-sections so that readers can fully understand the advantages and disadvantages of the relevant transducers—depending on the design, transduction mode, and final applications. Smart Sensors for Environmental and Medical Applications covers all major aspects of the field of smart chemical sensors, including working principle and related theory, sensor materials, classification of respective transducer type, relevant fabrication processes, methods for data analysis, and suitable applications. Chapters address field effect transistors technologies for biological and chemical sensors, mammalian cell–based electrochemical sensors for label-free monitoring of analytes, electronic tongues, chemical sensors based on metal oxides, metal oxide (MOX) gas sensor electronic interfaces, and more. Addressing the limitations and challenges in obtaining state-of-the-art smart biochemical sensors, this book: Balances the fundamentals of sensor design, fabrication, characterization, and analysis with advanced methods Categorizes sensors into sub-types and describes their working, focusing on prominent applications Describes instrumentation and IoT networking methods of chemical transducers that can be used for inexpensive, accurate detection in commercialized smart chemical sensors Covers monitoring of food spoilage using polydiacetylene- and liposome-based sensors; smart and intelligent E-nose for sensitive and selective chemical sensing applications; odor sensing system; and microwave chemical sensors Smart Sensors for Environmental and Medical Applications is an important book for senior-level undergraduate and graduate students learning about this high-performance technology and its many applications. It will also inform practitioners and researchers involved in the creation and use of smart sensors.
Smart Sensors for Environmental and Medical Applications
Author: Hamida Hallil
Publisher: John Wiley & Sons
ISBN: 1119587344
Category : Technology & Engineering
Languages : en
Pages : 240
Book Description
Provides an introduction to the topic of smart chemical sensors, along with an overview of the state of the art based on potential applications This book presents a comprehensive overview of chemical sensors, ranging from the choice of material to sensor validation, modeling, simulation, and manufacturing. It discusses the process of data collection by intelligent techniques such as deep learning, multivariate analysis, and others. It also incorporates different types of smart chemical sensors and discusses each under a common set of sub-sections so that readers can fully understand the advantages and disadvantages of the relevant transducers—depending on the design, transduction mode, and final applications. Smart Sensors for Environmental and Medical Applications covers all major aspects of the field of smart chemical sensors, including working principle and related theory, sensor materials, classification of respective transducer type, relevant fabrication processes, methods for data analysis, and suitable applications. Chapters address field effect transistors technologies for biological and chemical sensors, mammalian cell–based electrochemical sensors for label-free monitoring of analytes, electronic tongues, chemical sensors based on metal oxides, metal oxide (MOX) gas sensor electronic interfaces, and more. Addressing the limitations and challenges in obtaining state-of-the-art smart biochemical sensors, this book: Balances the fundamentals of sensor design, fabrication, characterization, and analysis with advanced methods Categorizes sensors into sub-types and describes their working, focusing on prominent applications Describes instrumentation and IoT networking methods of chemical transducers that can be used for inexpensive, accurate detection in commercialized smart chemical sensors Covers monitoring of food spoilage using polydiacetylene- and liposome-based sensors; smart and intelligent E-nose for sensitive and selective chemical sensing applications; odor sensing system; and microwave chemical sensors Smart Sensors for Environmental and Medical Applications is an important book for senior-level undergraduate and graduate students learning about this high-performance technology and its many applications. It will also inform practitioners and researchers involved in the creation and use of smart sensors.
Publisher: John Wiley & Sons
ISBN: 1119587344
Category : Technology & Engineering
Languages : en
Pages : 240
Book Description
Provides an introduction to the topic of smart chemical sensors, along with an overview of the state of the art based on potential applications This book presents a comprehensive overview of chemical sensors, ranging from the choice of material to sensor validation, modeling, simulation, and manufacturing. It discusses the process of data collection by intelligent techniques such as deep learning, multivariate analysis, and others. It also incorporates different types of smart chemical sensors and discusses each under a common set of sub-sections so that readers can fully understand the advantages and disadvantages of the relevant transducers—depending on the design, transduction mode, and final applications. Smart Sensors for Environmental and Medical Applications covers all major aspects of the field of smart chemical sensors, including working principle and related theory, sensor materials, classification of respective transducer type, relevant fabrication processes, methods for data analysis, and suitable applications. Chapters address field effect transistors technologies for biological and chemical sensors, mammalian cell–based electrochemical sensors for label-free monitoring of analytes, electronic tongues, chemical sensors based on metal oxides, metal oxide (MOX) gas sensor electronic interfaces, and more. Addressing the limitations and challenges in obtaining state-of-the-art smart biochemical sensors, this book: Balances the fundamentals of sensor design, fabrication, characterization, and analysis with advanced methods Categorizes sensors into sub-types and describes their working, focusing on prominent applications Describes instrumentation and IoT networking methods of chemical transducers that can be used for inexpensive, accurate detection in commercialized smart chemical sensors Covers monitoring of food spoilage using polydiacetylene- and liposome-based sensors; smart and intelligent E-nose for sensitive and selective chemical sensing applications; odor sensing system; and microwave chemical sensors Smart Sensors for Environmental and Medical Applications is an important book for senior-level undergraduate and graduate students learning about this high-performance technology and its many applications. It will also inform practitioners and researchers involved in the creation and use of smart sensors.
Potentials and Trends in Biomimetics
Author: Arnim Gleich
Publisher: Springer Science & Business Media
ISBN: 3642052460
Category : Technology & Engineering
Languages : en
Pages : 202
Book Description
There is a wide consensus about the necessity of sustainable development. There is also a consensus that wide areas of our economy, industry, and technology and the life styles in industrialized countries are not susta- able. Science and technology are widely regarded as (main) causes for this situation. Issues in this context comprise the generally low resource ef- ciency, an increased and mostly undebated technological power, an - creased invasiveness of modern technologies, increasing amounts and - versity of pollutants, and high technological risks. On the other hand science and technology are also regarded as (main) solution providers towards more sustainability. Thus the question is which type of science and technology is rather a part of the problem, and which type is rather a part of the solution? ‘Learning from nature’ may give some orientation in this context. B- mimetics and bionics are widely regarded as being a part of the solution.
Publisher: Springer Science & Business Media
ISBN: 3642052460
Category : Technology & Engineering
Languages : en
Pages : 202
Book Description
There is a wide consensus about the necessity of sustainable development. There is also a consensus that wide areas of our economy, industry, and technology and the life styles in industrialized countries are not susta- able. Science and technology are widely regarded as (main) causes for this situation. Issues in this context comprise the generally low resource ef- ciency, an increased and mostly undebated technological power, an - creased invasiveness of modern technologies, increasing amounts and - versity of pollutants, and high technological risks. On the other hand science and technology are also regarded as (main) solution providers towards more sustainability. Thus the question is which type of science and technology is rather a part of the problem, and which type is rather a part of the solution? ‘Learning from nature’ may give some orientation in this context. B- mimetics and bionics are widely regarded as being a part of the solution.
The British National Bibliography
Author: Arthur James Wells
Publisher:
ISBN:
Category : Bibliography, National
Languages : en
Pages : 1294
Book Description
Publisher:
ISBN:
Category : Bibliography, National
Languages : en
Pages : 1294
Book Description
Science Breakthroughs to Advance Food and Agricultural Research by 2030
Author: National Academies of Sciences, Engineering, and Medicine
Publisher: National Academies Press
ISBN: 0309473926
Category : Science
Languages : en
Pages : 243
Book Description
For nearly a century, scientific advances have fueled progress in U.S. agriculture to enable American producers to deliver safe and abundant food domestically and provide a trade surplus in bulk and high-value agricultural commodities and foods. Today, the U.S. food and agricultural enterprise faces formidable challenges that will test its long-term sustainability, competitiveness, and resilience. On its current path, future productivity in the U.S. agricultural system is likely to come with trade-offs. The success of agriculture is tied to natural systems, and these systems are showing signs of stress, even more so with the change in climate. More than a third of the food produced is unconsumed, an unacceptable loss of food and nutrients at a time of heightened global food demand. Increased food animal production to meet greater demand will generate more greenhouse gas emissions and excess animal waste. The U.S. food supply is generally secure, but is not immune to the costly and deadly shocks of continuing outbreaks of food-borne illness or to the constant threat of pests and pathogens to crops, livestock, and poultry. U.S. farmers and producers are at the front lines and will need more tools to manage the pressures they face. Science Breakthroughs to Advance Food and Agricultural Research by 2030 identifies innovative, emerging scientific advances for making the U.S. food and agricultural system more efficient, resilient, and sustainable. This report explores the availability of relatively new scientific developments across all disciplines that could accelerate progress toward these goals. It identifies the most promising scientific breakthroughs that could have the greatest positive impact on food and agriculture, and that are possible to achieve in the next decade (by 2030).
Publisher: National Academies Press
ISBN: 0309473926
Category : Science
Languages : en
Pages : 243
Book Description
For nearly a century, scientific advances have fueled progress in U.S. agriculture to enable American producers to deliver safe and abundant food domestically and provide a trade surplus in bulk and high-value agricultural commodities and foods. Today, the U.S. food and agricultural enterprise faces formidable challenges that will test its long-term sustainability, competitiveness, and resilience. On its current path, future productivity in the U.S. agricultural system is likely to come with trade-offs. The success of agriculture is tied to natural systems, and these systems are showing signs of stress, even more so with the change in climate. More than a third of the food produced is unconsumed, an unacceptable loss of food and nutrients at a time of heightened global food demand. Increased food animal production to meet greater demand will generate more greenhouse gas emissions and excess animal waste. The U.S. food supply is generally secure, but is not immune to the costly and deadly shocks of continuing outbreaks of food-borne illness or to the constant threat of pests and pathogens to crops, livestock, and poultry. U.S. farmers and producers are at the front lines and will need more tools to manage the pressures they face. Science Breakthroughs to Advance Food and Agricultural Research by 2030 identifies innovative, emerging scientific advances for making the U.S. food and agricultural system more efficient, resilient, and sustainable. This report explores the availability of relatively new scientific developments across all disciplines that could accelerate progress toward these goals. It identifies the most promising scientific breakthroughs that could have the greatest positive impact on food and agriculture, and that are possible to achieve in the next decade (by 2030).
Electronic Noses and Tongues in Food Science
Author: Maria Luz Rodriguez Mendez
Publisher: Academic Press
ISBN: 0128004029
Category : Technology & Engineering
Languages : en
Pages : 334
Book Description
Electronic Noses and Tongues in Food Science describes the electronic products of advanced chemical and physical sciences combined with intuitive integration of microprocessors, advanced bioinformatics and statistics. These include, for example, voltammetric, bio-electronic, piezoelectric platforms made from a variety of components including, nanoparticles, enzyme biosensors, heavy metals, graphite-epoxy composites, metal oxide semiconductors, microelectrodes, microfluidic channels, pre-manufactured gas sensors, redox enzymes and others and is an ideal resource for understanding and utilizing their power in Food Science settings. Devices used to analyse one particular food item can theoretically be adapted for other food items or components. This does not just mean the re-deploying the physical platforms but also the mode of bioinformatic and statistical analysis. This includes artificial neural networks (ANN), linear discriminant analysis (LDA), partial least squares (PLS), principal component analysis (PCA) etc. In other words, there is cross transference of chemistry, physics, concepts, techniques, findings and approaches from one food to another. Electronic noses and tongues are two of these devices but are advancing in application and importance. This book provides examples of the use of electronic noses and tongues to characterise components that contribute to sensory or compositional profiles, from ripening to harvesting and from storage of raw materials to packaging and consumption. These devises are suitable for high-throughput analysis, quality control or to determine the nature and extent of spoilage and adulteration, and have also been used to ascertain the geographical origins of food and mixtures. - Presents latest developments in the application of electronic nose and tongue technologies to a variety of food-specific needs - Includes both electronic nose, electronic tongue and combined technology insights - Each chapter has sections on: The physical and chemical platforms; Analysis of specific foods; Applications to other foods and areas of food science
Publisher: Academic Press
ISBN: 0128004029
Category : Technology & Engineering
Languages : en
Pages : 334
Book Description
Electronic Noses and Tongues in Food Science describes the electronic products of advanced chemical and physical sciences combined with intuitive integration of microprocessors, advanced bioinformatics and statistics. These include, for example, voltammetric, bio-electronic, piezoelectric platforms made from a variety of components including, nanoparticles, enzyme biosensors, heavy metals, graphite-epoxy composites, metal oxide semiconductors, microelectrodes, microfluidic channels, pre-manufactured gas sensors, redox enzymes and others and is an ideal resource for understanding and utilizing their power in Food Science settings. Devices used to analyse one particular food item can theoretically be adapted for other food items or components. This does not just mean the re-deploying the physical platforms but also the mode of bioinformatic and statistical analysis. This includes artificial neural networks (ANN), linear discriminant analysis (LDA), partial least squares (PLS), principal component analysis (PCA) etc. In other words, there is cross transference of chemistry, physics, concepts, techniques, findings and approaches from one food to another. Electronic noses and tongues are two of these devices but are advancing in application and importance. This book provides examples of the use of electronic noses and tongues to characterise components that contribute to sensory or compositional profiles, from ripening to harvesting and from storage of raw materials to packaging and consumption. These devises are suitable for high-throughput analysis, quality control or to determine the nature and extent of spoilage and adulteration, and have also been used to ascertain the geographical origins of food and mixtures. - Presents latest developments in the application of electronic nose and tongue technologies to a variety of food-specific needs - Includes both electronic nose, electronic tongue and combined technology insights - Each chapter has sections on: The physical and chemical platforms; Analysis of specific foods; Applications to other foods and areas of food science
Biologically Inspired Robotics
Author: Yunhui Liu
Publisher: CRC Press
ISBN: 1439854882
Category : Medical
Languages : en
Pages : 343
Book Description
Robotic engineering inspired by biology—biomimetics—has many potential applications: robot snakes can be used for rescue operations in disasters, snake-like endoscopes can be used in medical diagnosis, and artificial muscles can replace damaged muscles to recover the motor functions of human limbs. Conversely, the application of robotics technology to our understanding of biological systems and behaviors—biorobotic modeling and analysis—provides unique research opportunities: robotic manipulation technology with optical tweezers can be used to study the cell mechanics of human red blood cells, a surface electromyography sensing system can help us identify the relation between muscle forces and hand movements, and mathematical models of brain circuitry may help us understand how the cerebellum achieves movement control. Biologically Inspired Robotics contains cutting-edge material—considerably expanded and with additional analysis—from the 2009 IEEE International Conference on Robotics and Biomimetics (ROBIO). These 16 chapters cover both biomimetics and biorobotic modeling/analysis, taking readers through an exploration of biologically inspired robot design and control, micro/nano bio-robotic systems, biological measurement and actuation, and applications of robotics technology to biological problems. Contributors examine a wide range of topics, including: A method for controlling the motion of a robotic snake The design of a bionic fitness cycle inspired by the jaguar The use of autonomous robotic fish to detect pollution A noninvasive brain-activity scanning method using a hybrid sensor A rehabilitation system for recovering motor function in human hands after injury Human-like robotic eye and head movements in human–machine interactions A state-of-the-art resource for graduate students and researchers in the fields of control engineering, robotics, and biomedical engineering, this text helps readers understand the technology and principles in this emerging field.
Publisher: CRC Press
ISBN: 1439854882
Category : Medical
Languages : en
Pages : 343
Book Description
Robotic engineering inspired by biology—biomimetics—has many potential applications: robot snakes can be used for rescue operations in disasters, snake-like endoscopes can be used in medical diagnosis, and artificial muscles can replace damaged muscles to recover the motor functions of human limbs. Conversely, the application of robotics technology to our understanding of biological systems and behaviors—biorobotic modeling and analysis—provides unique research opportunities: robotic manipulation technology with optical tweezers can be used to study the cell mechanics of human red blood cells, a surface electromyography sensing system can help us identify the relation between muscle forces and hand movements, and mathematical models of brain circuitry may help us understand how the cerebellum achieves movement control. Biologically Inspired Robotics contains cutting-edge material—considerably expanded and with additional analysis—from the 2009 IEEE International Conference on Robotics and Biomimetics (ROBIO). These 16 chapters cover both biomimetics and biorobotic modeling/analysis, taking readers through an exploration of biologically inspired robot design and control, micro/nano bio-robotic systems, biological measurement and actuation, and applications of robotics technology to biological problems. Contributors examine a wide range of topics, including: A method for controlling the motion of a robotic snake The design of a bionic fitness cycle inspired by the jaguar The use of autonomous robotic fish to detect pollution A noninvasive brain-activity scanning method using a hybrid sensor A rehabilitation system for recovering motor function in human hands after injury Human-like robotic eye and head movements in human–machine interactions A state-of-the-art resource for graduate students and researchers in the fields of control engineering, robotics, and biomedical engineering, this text helps readers understand the technology and principles in this emerging field.
The Global Technology Revolution 2020, In-Depth Analyses: Bio/Nano/Materials/Information Trends, Drivers, Barriers, and Social Implications
Author: Richard Silberglitt
Publisher: Rand Corporation
ISBN: 0833041142
Category : Technology & Engineering
Languages : en
Pages : 332
Book Description
In 2020, areas of particular importance for technology trends will include biotechnology, nanotechnology, materials technology, and information technology. This report, the companion document to The Global Technology Revolution 2020, Executive Summary (Silberglitt et al., MG-475-NIC, 2006), assesses in detail a sample of 29 countries with respect to their ability to acquire and implement 16 key technology applications.
Publisher: Rand Corporation
ISBN: 0833041142
Category : Technology & Engineering
Languages : en
Pages : 332
Book Description
In 2020, areas of particular importance for technology trends will include biotechnology, nanotechnology, materials technology, and information technology. This report, the companion document to The Global Technology Revolution 2020, Executive Summary (Silberglitt et al., MG-475-NIC, 2006), assesses in detail a sample of 29 countries with respect to their ability to acquire and implement 16 key technology applications.
Tea in Health and Disease Prevention
Author: Victor R Preedy
Publisher: Elsevier
ISBN: 0443141592
Category : Technology & Engineering
Languages : en
Pages : 1030
Book Description
While there is a nearly universal agreement that drinking tea can benefit health, information on the benefits or adverse effects of drinking tea is scattered, leaving definitive answers difficult to ascertain. Tea in Health and Disease Prevention, Second Edition, once again addresses this problem, bringing together all the latest and most relevant information on tea and its health effects into one comprehensive resource. This book covers compounds in black, green, and white teas and explores their health implications, first more generally, then in terms of specific organ systems and diseases. With over 75% brand new content, this fully reorganized, updated edition covers a wider range of tea varieties and beneficial compounds found in tea, such as epigallocatechin gallate and antioxidants.Tea in Health and Disease Prevention, Second Edition, is an organized, efficient resource that will help readers find quick answers to questions and will help inspire further studies for those interested in tea research. This is a must-have reference for researchers in food science and nutrition, as well as nutritionists and dieticians. - Covers and compares features, benefits, and potential negative effects of the most important types of tea, including green, black, and white - Identifies therapeutic benefits of teas for new product development - Offers a "one stop shop" for research in this area, compiling both foundational and cutting-edge topics into one resource - Includes a dictionary of key terms, other health effects of tea or extracts, and a summary point section within each chapter for a quick reference
Publisher: Elsevier
ISBN: 0443141592
Category : Technology & Engineering
Languages : en
Pages : 1030
Book Description
While there is a nearly universal agreement that drinking tea can benefit health, information on the benefits or adverse effects of drinking tea is scattered, leaving definitive answers difficult to ascertain. Tea in Health and Disease Prevention, Second Edition, once again addresses this problem, bringing together all the latest and most relevant information on tea and its health effects into one comprehensive resource. This book covers compounds in black, green, and white teas and explores their health implications, first more generally, then in terms of specific organ systems and diseases. With over 75% brand new content, this fully reorganized, updated edition covers a wider range of tea varieties and beneficial compounds found in tea, such as epigallocatechin gallate and antioxidants.Tea in Health and Disease Prevention, Second Edition, is an organized, efficient resource that will help readers find quick answers to questions and will help inspire further studies for those interested in tea research. This is a must-have reference for researchers in food science and nutrition, as well as nutritionists and dieticians. - Covers and compares features, benefits, and potential negative effects of the most important types of tea, including green, black, and white - Identifies therapeutic benefits of teas for new product development - Offers a "one stop shop" for research in this area, compiling both foundational and cutting-edge topics into one resource - Includes a dictionary of key terms, other health effects of tea or extracts, and a summary point section within each chapter for a quick reference
Rising Above the Gathering Storm
Author: Institute of Medicine
Publisher: National Academies Press
ISBN: 0309100399
Category : Political Science
Languages : en
Pages : 590
Book Description
In a world where advanced knowledge is widespread and low-cost labor is readily available, U.S. advantages in the marketplace and in science and technology have begun to erode. A comprehensive and coordinated federal effort is urgently needed to bolster U.S. competitiveness and pre-eminence in these areas. This congressionally requested report by a pre-eminent committee makes four recommendations along with 20 implementation actions that federal policy-makers should take to create high-quality jobs and focus new science and technology efforts on meeting the nation's needs, especially in the area of clean, affordable energy: 1) Increase America's talent pool by vastly improving K-12 mathematics and science education; 2) Sustain and strengthen the nation's commitment to long-term basic research; 3) Develop, recruit, and retain top students, scientists, and engineers from both the U.S. and abroad; and 4) Ensure that the United States is the premier place in the world for innovation. Some actions will involve changing existing laws, while others will require financial support that would come from reallocating existing budgets or increasing them. Rising Above the Gathering Storm will be of great interest to federal and state government agencies, educators and schools, public decision makers, research sponsors, regulatory analysts, and scholars.
Publisher: National Academies Press
ISBN: 0309100399
Category : Political Science
Languages : en
Pages : 590
Book Description
In a world where advanced knowledge is widespread and low-cost labor is readily available, U.S. advantages in the marketplace and in science and technology have begun to erode. A comprehensive and coordinated federal effort is urgently needed to bolster U.S. competitiveness and pre-eminence in these areas. This congressionally requested report by a pre-eminent committee makes four recommendations along with 20 implementation actions that federal policy-makers should take to create high-quality jobs and focus new science and technology efforts on meeting the nation's needs, especially in the area of clean, affordable energy: 1) Increase America's talent pool by vastly improving K-12 mathematics and science education; 2) Sustain and strengthen the nation's commitment to long-term basic research; 3) Develop, recruit, and retain top students, scientists, and engineers from both the U.S. and abroad; and 4) Ensure that the United States is the premier place in the world for innovation. Some actions will involve changing existing laws, while others will require financial support that would come from reallocating existing budgets or increasing them. Rising Above the Gathering Storm will be of great interest to federal and state government agencies, educators and schools, public decision makers, research sponsors, regulatory analysts, and scholars.
Bio-Inspired Innovation and National Security
Author: National Defense University
Publisher: NDU Press
ISBN: 1780390408
Category : History
Languages : en
Pages : 356
Book Description
Despite the vital importance of the emerging area of biotechnology and its role in defense planning and policymaking, no definitive book has been written on the topic for the defense policymaker, the military student, and the private-sector bioscientist interested in the "emerging opportunities market" of national security. This edited volume is intended to help close this gap and provide the necessary backdrop for thinking strategically about biology in defense planning and policymaking. This volume is about applications of the biological sciences, here called "biologically inspired innovations," to the military. Rather than treating biology as a series of threats to be dealt with, such innovations generally approach the biological sciences as a set of opportunities for the military to gain strategic advantage over adversaries. These opportunities range from looking at everything from genes to brains, from enhancing human performance to creating renewable energy, from sensing the environment around us to harnessing its power.
Publisher: NDU Press
ISBN: 1780390408
Category : History
Languages : en
Pages : 356
Book Description
Despite the vital importance of the emerging area of biotechnology and its role in defense planning and policymaking, no definitive book has been written on the topic for the defense policymaker, the military student, and the private-sector bioscientist interested in the "emerging opportunities market" of national security. This edited volume is intended to help close this gap and provide the necessary backdrop for thinking strategically about biology in defense planning and policymaking. This volume is about applications of the biological sciences, here called "biologically inspired innovations," to the military. Rather than treating biology as a series of threats to be dealt with, such innovations generally approach the biological sciences as a set of opportunities for the military to gain strategic advantage over adversaries. These opportunities range from looking at everything from genes to brains, from enhancing human performance to creating renewable energy, from sensing the environment around us to harnessing its power.