Reactive Extrusion

Extrusion is by far the most important and the oldest processing and shaping method for thermoplastic polymers. This process concerns almost all synthetic polymers, as well as elastomers or food materials. Single-screw extrusion is mainly used nowadays to manufacture finished goods or semi-finished products. More than 90 million tons of thermoplastics are therefore processed every year. Twin-screw extrusion may be divided into two systems: contra-rotating systems used within the context of PVC extrusion, for the manufacture of pipes or profiles; and co-rotating systems experiencing nowadays a very significant development, because of their significant adaptability and flexibility, which enables the manufacture of specific materials (polymer alloys, thermoplastic elastomers, filled polymers, nanocomposites). Extrusion is carried out by passing molten polymer through a tool called die that will give the product its final shape (films and sheets, rolled products, and electric cables). Thanks to the design of dies, we obtain at the output a product with controlled dimensions, uniform speeds and homogeneous temperatures. The book will discuss the same production types, but only in the case of coextrusion flows, i.e. multilayer stratified products. First of all, we will present in this book the physics of the mechanisms at stake, then propose more or less complex models in order to describe these mechanisms and then go forward in the interpretation of results and the control of condition flows.

The only up-to-date book on this important technology, Extrusion Processing Technology: Food and Non-Food Biomaterials bridges the gap between the principles of extrusion science and the practical «know how» of operational engineers and technicians. Written by internationally renowned experts with over forty years of experience between them, this valuable reference for food scientists, food engineers, chemical engineers, and students includes coverage of new, greener technologies as well as case studies to illustrate the practical, real-world application of the principles in various settings.

In a reactive distillation column, both the chemical conversion and the distillative separation of the product mixture are carried out simultaneously. Through this integrative strategy, chemical equilibrium limitations can be overcome, higher selectivities can be achieved and heat of reaction can be directly used for distillation. Increased process efficiency and reduction of investments and operational costs are the direct results of this approach. Highly renowned international experts from both industry and academia review the state-of-the-art and the future directions in application, design, analysis and control of Reactive Distillation processes. Part I surveys various industrial applications and covers both established large scale processes as well as new chemical reaction schemes with high future potential. Part II provides the vital details for analysis of reactive phase equilibria, and discusses the importance of chemical reaction kinetics, while Part III focuses on identifying feasible column configurations and designing their internal structure. Analysis and control of the complex dynamic and steady-state behavior of reactive distillation processes are described in Part IV. Reactive Distillation – a very promising alternative to conventional reaction-distillation flow schemes.

Hot-melt extrusion (HME) – melting a substance and forcing it through an orifice under controlled conditions to form a new material – is an emerging processing technology in the pharmaceutical industry for the preparation of various dosage forms and drug delivery systems, for example granules and sustained release tablets. Hot-Melt Extrusion: Pharmaceutical Applications covers the main instrumentation, operation principles and theoretical background of HME. It then focuses on HME drug delivery systems, dosage forms and clinical studies (including pharmacokinetics and bioavailability) of HME products. Finally, the book includes some recent and novel HME applications, scale -up considerations and regulatory issues. Topics covered include: principles and die design of single screw extrusion twin screw extrusion techniques and practices in the laboratory and on production scale HME developments for the pharmaceutical industry solubility parameters for prediction of drug/polymer miscibility in HME formulations the influence of plasticizers in HME applications of polymethacrylate polymers in HME HME of ethylcellulose, hypromellose, and polyethylene oxide bioadhesion properties of polymeric films produced by HME taste masking using HME clinical studies, bioavailability and pharmacokinetics of HME products injection moulding and HME processing for pharmaceutical materials laminar dispersive & distributive mixing with dissolution and applications to HME technological considerations related to scale-up of HME processes devices and implant systems by HME an FDA perspective on HME product and process understanding improved process understanding and control of an HME process with near-infrared spectroscopy Hot-Melt Extrusion: Pharmaceutical Applications is an essential multidisciplinary guide to the emerging pharmaceutical uses of this processing technology for researchers in academia and industry working in drug formulation and delivery, pharmaceutical engineering and processing, and polymers and materials science. This is the first book from our brand new series Advances in Pharmaceutical Technology. Find out more about the series here.

Teaches the application of Reactive Transport Modeling (RTM) for subsurface systems in order to expedite the understanding of the behavior of complex geological systems This book lays out the basic principles and approaches of Reactive Transport Modeling (RTM) for surface and subsurface environments, presenting specific workflows and applications. The techniques discussed are being increasingly commonly used in a wide range of research fields, and the information provided covers fundamental theory, practical issues in running reactive transport models, and how to apply techniques in specific areas. The need for RTM in engineered facilities, such as nuclear waste repositories or CO2 storage sites, is ever increasing, because the prediction of the future evolution of these systems has become a legal obligation. With increasing recognition of the power of these approaches, and their widening adoption, comes responsibility to ensure appropriate application of available tools. This book aims to provide the requisite understanding of key aspects of RTM, and in doing so help identify and thus avoid potential pitfalls. Reactive Transport Modeling covers: the application of RTM for CO2 sequestration and geothermal energy development; reservoir quality prediction; modeling diagenesis; modeling geochemical processes in oil & gas production; modeling gas hydrate production; reactive transport in fractured and porous media; reactive transport studies for nuclear waste disposal; reactive flow modeling in hydrothermal systems; and modeling biogeochemical processes. Key features include: A comprehensive reference for scientists and practitioners entering the area of reactive transport modeling (RTM) Presented by internationally known experts in the field Covers fundamental theory, practical issues in running reactive transport models, and hands-on examples for applying techniques in specific areas Teaches readers to appreciate the power of RTM and to stimulate usage and application Reactive Transport Modeling is written for graduate students and researchers in academia, government laboratories, and industry who are interested in applying reactive transport modeling to the topic of their research. The book will also appeal to geochemists, hydrogeologists, geophysicists, earth scientists, environmental engineers, and environmental chemists.

Closing a gap in the scientifi c literature, this first comprehensive introduction to the topic is based on current best practice in one of the largest pharmaceutical companies worldwide. The first chapters trace the development of our understanding of drug metabolite toxicity, covering basic concepts and techniques in the process, while the second part details chemical toxicophores that are prone to reactive metabolite formation. This section also reviews the various drug-metabolizing enzymes that can participate in catalyzing reactive metabolite formation, including a discussion of the structure-toxicity relationships for drugs. Two chapters are dedicated to the currently hot topics of herbal constituents and IADRs. The next part covers current strategies and approaches to evaluate the reactive metabolite potential of new drug candidates, both by predictive and by bioanalytical methods. There then follows an in-depth analysis of the toxicological potential of the top 200 prescription drugs, illustrating the power and the limits of the toxicophore concept, backed by numerous case studies. Finally, a risk-benefi t approach to managing the toxicity risk of reactive metabolite-prone drugs is presented. Since the authors carefully develop the knowledge needed, from fundamental considerations to current industry standards, no degree in pharmacology is required to read this book, making it perfect for medicinal chemists without in-depth pharmacology training.

Photosynthesis and the complex network within plants is becoming more important than ever, because of the earth’s changing climate. In addition, the concepts can be used in other areas, and the science itself is useful in practical applications in many branches of science, including medicine, biology, biophysics, and chemistry. This original, groundbreaking work by two highly experienced and well-known scientists introduces a new and different approach to thinking about living organisms, what we can learn from them, and how we can use the concepts within their scientific makeup in practice. This book describes the principles of complex signaling networks enabling spatiotemporally-directed macroscopic processes by the coupling of systems leading to a bottom-up information transfer in photosynthetic organisms. Top-down messengers triggered by macroscopic actuators like sunlight, gravity, environment or stress lead to an activation of the gene regulation on the molecular level. Mainly the generation and monitoring, as well the role of reactive oxygen species in photosynthetic organisms as typical messengers in complex networks, are described. A theoretical approach according to the principle of synergetics is presented to model light absorption, electron transfer and membrane dynamics in plants. A special focus will be attended to nonlinear processes that form the basic principle for the accumulation of energy reservoirs and large forces enabling the dynamics of macroscopic devices. This volume is a must-have for any scientist, student, or engineer working with photosynthesis. The concepts herein are not available anywhere else, in any other format, and it is truly a groundbreaking work with sure to be long-lasting effects on the scientific community.

After an overview of the fundamentals, limitations, and scope of reactive distillation, this book uses rigorous models for steady-state design and dynamic analysis of different types of reactive distillation columns and quantitatively compares the economics of reactive distillation columns with conventional multi-unit processes. It goes beyond traditional steady-state design that primarily considers the capital investment and energy costs when analyzing the control structure and the dynamic robustness of disturbances, and discusses how to maximize the economic and environmental benefits of reactive distillation technology.

The chemistry of reactive intermediates is central to a modern mechanistic and quantitative understanding of organic chemistry. Moreover, it underlies a significant portion of modern synthetic chemistry and is integral to a molecular view of biological chemistry. Reviews in Reactive Intermediate Chemistry presents an up-to-date, authoritative guide to this fundamental topic. Although it follows Reactive Intermediate Chemistry by the same authors, it serves as a free-standing resource for the entire chemical and biochemical community. The book includes: Relevant, practical applications Coverage of such topics as mass spectrometry methods, reactive intermediates in interstellar medium, quantum mechanical tunnelling, solvent effects, reactive intermediates in biochemical processes, and excited state surfaces Discussions of emerging areas, particularly those involving dynamics and theories Concluding sections identifying key directions for future research are provided at the end of each chapter

Describes the basics of ROS metabolism in plants and examines the broad range of ROS signaling mechanisms New discoveries about the effects of reactive oxygen species (ROS) on plants have turned ROS from being considered a bane into a boon, because their roles have been discovered in many plant developmental processes as signaling molecules. This comprehensive book teaches about the role of ROS metabolism in plants and how they affect various developmental processes. It also discusses in detail the advancements made in understanding the ROS signaling. Reactive Oxygen Species in Plants: Boon Or Bane – Revisiting the Role of ROS begins by presenting the basic introduction to ROS and deciphers the detailed knowledge in ROS research. It then examines the broad range of ROS signaling mechanisms as well as how they may be beneficial for plants and human beings. This book also describes both the bane and boon aspects of ROS with their impact on plants, and how the recent revelations have compelled us to rethink ROS turning from stressors to plant regulators. ● Compiles, for the first time, the wholesome knowledge in ROS research and their cellular signaling ● Includes new discoveries and in-depth discussions about the advancements made in the field ● Discusses reactive oxygen species which are involved in a broad range of biological processes Reactive Oxygen Species in Plants: Boon Or Bane – Revisiting the Role of ROS will help scientists to utilize the functions of ROS signaling for plants and also enable readers to gain a deeper knowledge of ROS research and signaling. It is highly recommended for researchers, scientists, and academicians in plant science as well for advanced undergraduate and postgraduate students.