This timely and unique publication is designed for graduate students and researchers in inorganic and materials chemistry and covers bonding models and applications of symmetry concepts to chemical systems. The book discusses the quantum mechanical basis for molecular orbital concepts, the connections between molecular orbitals and localized views of bonding, group theory, bonding models for a variety of compounds, and the extension of these ideas to solid state materials in band theory. Unlike other books, the concepts are made tangible to the readers by guiding them through their implementation in MATLAB functions. No background in MATLAB or computer programming is needed; the book will provide the necessary skills. Key Features Visualization of the Postulates of Quantum Mechanics to build conceptual understanding MATLAB functions for rendering molecular geometries and orbitals Do-it-yourself approach to building a molecular orbital and band theory program Introduction to Group Theory harnessing the 3D graphing capabilities of MATLAB Online access to a growing collection of applications of the core material and other appendices Bonding through Code is ideal for first-year graduate students and advanced undergraduates in chemistry, materials science, and physics. Researchers wishing to gain new tools for theoretical analysis or deepen their understanding of bonding phenomena can also benefit from this text. About the Author Daniel Fredrickson is a Professor in the Department of Chemistry at the University of Wisconsin-Madison, where his research group focuses on understanding and harnessing the structural chemistry of intermetallic phases using a combination of theory and experiment. His interests in crystals, structure, and bonding can be traced to his undergraduate research at the University of Washington (B.S. in Biochemistry, 2000) with Prof. Bart Kahr, his Ph.D. studies at Cornell University (2000-2005) with Profs. Stephen Lee and Roald Hoffmann, and his post-doctoral work with Prof. Sven Lidin at Stockholm University (2005-2008). As part of his teaching at UW-Madison since 2009, he has worked to enhance his department's graduate course, Physical Inorganic Chemistry I: Symmetry and Bonding, through the incorporation of new material and the development of computer-based exercises.

As 2019 has been declared the International Year of the Periodic Table, it is appropriate that Structure and Bonding marks this anniversary with two special volumes. In 1869 Dmitri Ivanovitch Mendeleev first proposed his periodic table of the elements. He is given the major credit for proposing the conceptual framework used by chemists to systematically inter-relate the chemical properties of the elements. However, the concept of periodicity evolved in distinct stages and was the culmination of work by other chemists over several decades. For example, Newland's Law of Octaves marked an important step in the evolution of the periodic system since it represented the first clear statement that the properties of the elements repeated after intervals of 8. Mendeleev's predictions demonstrated in an impressive manner how the periodic table could be used to predict the occurrence and properties of new elements. Not all of his many predictions proved to be valid, but the discovery of scandium, gallium and germanium represented sufficient vindication of its utility and they cemented its enduring influence. Mendeleev's periodic table was based on the atomic weights of the elements and it was another 50 years before Moseley established that it was the atomic number of the elements, that was the fundamental parameter and this led to the prediction of further elements. Some have suggested that the periodic table is one of the most fruitful ideas in modern science and that it is comparable to Darwin's theory of evolution by natural selection, proposed at approximately the same time. There is no doubt that the periodic table occupies a central position in chemistry. In its modern form it is reproduced in most undergraduate inorganic textbooks and is present in almost every chemistry lecture room and classroom. This second volume provides chemists with an overview of the important role played by the Periodic Table in advancing our knowledge of solid state and bioinorganic chemistry. It also illustrates how it has been used to fine-tune the properties of compounds which have found commercial applications in catalysis, electronics, ceramics and in medicinal chemistry.

The book provides an in-depth discussion regarding inorganic ion exchangers for students, teachers, and researchers engaged in conducting research in chemical technology and related areas. Analytical chemists seeking simple and novel means of using easy-to-prepare chromatographic materials will find this book extremely informative. Inorganic Ion Exchangers in Chemical Analysis is unique in its discussion of column and planar chromatographic applications of amorphous synthetic inorganic ion exchangers. The book also covers the historical background of iorganic ion exchangers, their classification and present status, and the analytical aspects of these materials.

Powder diffraction is a widely used scientific technique in the characterization of materials with broad application in materials science, chemistry, physics, geology, pharmacology and archaeology. Powder Diffraction: Theory and Practice provides an advanced introductory text about modern methods and applications of powder diffraction in research and industry. The authors begin with a brief overview of the basic theory of diffraction from crystals and powders. Data collection strategies are described including x-ray, neutron and electron diffraction setups using modern day apparatus including synchrotron sources. Data corrections, essential for quantitative analysis are covered before the authors conclude with a discussion of the analysis methods themselves. The information is presented in a way that facilitates understanding the information content of the data, as well as best practices for collecting and analyzing data for quantitative analysis. This long awaited book condenses the knowledge of renowned experts in the field into a single, authoritative, overview of the application of powder diffraction in modern materials research. The book contains essential theory and introductory material for students and researchers wishing to learn how to apply the frontier methods of powder diffraction

This book presents the recent advances in the field of nanoscale science and engineering of ferroelectric thin films. It comprises two main parts, i.e. electrical characterization in nanoscale ferroelectric capacitor, and nano domain manipulation and visualization in ferroelectric materials. Well known le'adingexperts both in relevant academia and industry over the world (U.S., Japan, Germany, Switzerland, Korea) were invited to contribute to each chapter. The first part under the title of electrical characterization in nanoscale ferroelectric capacitors starts with Chapter 1, "Testing and characterization of ferroelectric thin film capacitors," written by Dr. I. K. Yoo. The author provides a comprehensive review on basic concepts and terminologies of ferroelectric properties and their testing methods. This chapter also covers reliability issues in FeRAMs that are crucial for commercialization of high density memory products. In Chapter 2, "Size effects in ferroelectric film capacitors: role ofthe film thickness and capacitor size," Dr. I. Stolichnov discusses the size effects both in in-plane and out-of-plane dimensions of the ferroelectric thin film. The author successfully relates the electric performance and domain dynamics with proposed models of charge injection and stress induced phase transition. The author's findings present both a challenging problem and the clue to its solution of reliably predicting the switching properties for ultra-thin ferroelectric capacitors. In Chapter 3, "Ferroelectric thin films for memory applications: nanoscale characterization by scanning force microscopy," Prof. A."

Optical Spectroscopy of Lanthanides: Magnetic and Hyperfine Interactions represents the sixth and final book by the late Brian Wybourne, an accomplished pioneer in the spectroscopy of rare earth ions, and Lidia Smentek, a leading theoretical physicist in the field. The book provides a definitive and up-to-date theoretical description of spectroscopic properties of lanthanides doped in various materials.

The book integrates computer-assisted calculations developed since Wybourne's classic publication on the topic. It contains useful Maple(TM) routines, discussions, and new aspects of the theory of f-electron systems. Establishing a unified basis for understanding state-of-the-art applications and techniques used in the field, the book reviews fundamentals based on Wybourne's graduate lectures, which include the theory of nuclei, the theory of angular momentum, Racah algebra, and effective tensor operators. It then describes magnetic and hyperfine interactions and their impact on the energy structure and transition amplitudes of the lanthanide ions. The text culminates with a relativistic description of "f"↔"f" electric and magnetic dipole transitions, covering sensitized luminescence and a new parametrization scheme of f-spectra.

Optical Spectroscopy of Lanthanides enables scientists to construct accurate and reliable theoretical models to elucidate lanthanides and their properties. This text is ideal for exploring a range of lanthanide applications including electronic data storage, lasers, superconductors, medicine, nuclear engineering, and nanomaterials.

This volume highlights the recent advances and state of art in the experimental and theoretical studies of organometallic magnets. A plethora of organic ligands such as Mannich-base derivatives, redox-active chromophores, cyanides, Schiff base among others are used to coordinate to 3d transition metals, 4f lanthanides and 5f actinides to design the molecular magnets. Deep analysis of the coordination sphere symmetry, electronic distribution, luminescence are investigated to perform magneto-structural correlation leading to a better understanding of the magnetic properties. Furthermore, the rationalization of the magnetic behavior can be reached using ab initio calculations. The multiple applications that these molecular magnets offer could revolutionize the high-density data storage, spintronics and quantum computing technologies. This volume provides a discussion of these topics from leading international experts and will be a useful reference for researchers working in this field.

It has long been recognized that metal spin states play a central role in the reactivity of important biomolecules, in industrial catalysis and in spin crossover compounds. As the fields of inorganic chemistry and catalysis move towards the use of cheap, non-toxic first row transition metals, it is essential to understand the important role of spin states in influencing molecular structure, bonding and reactivity. Spin States in Biochemistry and Inorganic Chemistry provides a complete picture on the importance of spin states for reactivity in biochemistry and inorganic chemistry, presenting both theoretical and experimental perspectives. The successes and pitfalls of theoretical methods such as DFT, ligand-field theory and coupled cluster theory are discussed, and these methods are applied in studies throughout the book. Important spectroscopic techniques to determine spin states in transition metal complexes and proteins are explained, and the use of NMR for the analysis of spin densities is described. Topics covered include: * DFT and ab initio wavefunction approaches to spin states * Experimental techniques for determining spin states * Molecular discovery in spin crossover * Multiple spin state scenarios in organometallic reactivity and gas phase reactions * Transition-metal complexes involving redox non-innocent ligands * Polynuclear iron sulfur clusters * Molecular magnetism * NMR analysis of spin densities This book is a valuable reference for researchers working in bioinorganic and inorganic chemistry, computational chemistry, organometallic chemistry, catalysis, spin-crossover materials, materials science, biophysics and pharmaceutical chemistry.

This book presents an original investigation into alternative photovoltaic absorbers. Solar power is a highly promising renewable energy solution; however, its success is hampered by the limited cost-effectiveness of current devices. The book assesses the photovoltaic performance of over 20 materials using state-of-the-art, first-principles methods. Adopting a computational approach, it investigates atomic-scale properties at a level of accuracy that is difficult to achieve using laboratory-based experimental techniques. Unlike many theoretical studies, it provides specific advice to those involved in experimental investigations. Further, it proposes directions for future research. This book advances the field of photovoltaics in three crucial ways: firstly, it identifies why one class of proposed materials cannot achieve high efficiency, while at the same time gaining insights that can be used to design future absorbers. Secondly, it shows that poor performance in the bismuth chalcohalides is not due to fundamental limitations, and can be overcome by finely controlling synthesis conditions. Lastly, it describes a range of new stable materials that are expected to show excellent photovoltaic performance.

Metals in pharmaceuticals have played an increasingly important role in medicine over the last century, particularly in cancer therapy and diagnostic imaging methods. Medicinal Applications of Coordination Chemistry focuses on the role that transition metals play in clinical applications. Medicinal Applications of Coordination Chemistry begins with a brief historical review and an introduction to the chemistry of d- and f- block metals. Subsequent sections discuss metallodrugs for a number of different applications, the design of new drugs and the relationship between structure and function. Key sections include diagnostic applications of metal compounds in anatomical and functional imaging, and therapeutic applications of metals compounds. This book is ideal for researchers in academia and industry and comes complete with examples of real life applications.

Breakthrough research and innovative science . . .

PROGRESS in Inorganic Chemistry

Nowhere is creative scientific talent busier than in the world of inorganic chemistry. This fascinating series provides the field of inorganic chemistry with a forum for critical and authoritative evaluations of advances in every area of the discipline. With contributions from internationally renowned chemists, this latest volume of Progress in Inorganic Chemistry continues to report the most recent advances with an innovative, cutting-edge style.

"This series is distinguished not only by its scope and breadth, but also by the depth and quality of the reviews."
–Journal of the American Chemical Society

"[This series] has won a deservedly honored place on the bookshelf of the chemist attempting to keep afloat in the torrent of original papers on inorganic chemistry."
–Chemistry in Britain

CONTENTS OF VOLUME 49

• Nonclassical Metal Carbonyls
  (Anthony J. Lupinetti and Steven H. Strauss, Colorado State University, Fort Collins, Colorado, and Gernot Frenking, Philipps-Universitat Marburg, Germany)
• The Influence of Ligands on Dirhodium(II) on Reactivity and Selectivity in Metal Carbene Reactions
  (Michael P. Doyle, University of Arizona, Tucson, Arizona, and Tong Ren, University of Miami, Coral Gables, Florida)
• Coordination Chemistry of Transition Metals with Hydrogen Chalcogenide and Hydrochalcogenido Ligands
  (Maurizio Peruzzini and Isaac De Los Rios, Instituto per lo Studio della Stereochimica ed Energetica dei Composti de Coordinazione, CNR, Firenze, Italy, and Antonio Romerosa, Universidad de Almeria, Spain)
• The Coordination Chemistry of Phosphinines, Their Polydentate and Macrocyclic Derivatives
  (Nicolas Mézailles, François Mathey, and Pascal le Floch, École Polytechnique, Palaiseau Cedex, France)
• Texaphyrins: Synthesis and Development of a Novel Class of Therapeutic Agents
  (Tarak D. Mody and Lei Fu, Pharmacyclics, Inc., Sunnyvale, California, and Jonathan L. Sessler, University of Texas at Austin, Texas)
• The Chemistry of Synthetic Fe-Mo-S Clusters and Their Relevance to the Structure and Function of the Fe-Mo-S Center in Nitrogenase
  (Steve M. Malinak, Albion College, Michigan, and Dimitri Coucouvanis, University of Michigan, Ann Arbor, Michigan)

Actinide elements and their chemistry have a significant number of applications. Bringing together contributions from the leading experts in the field, Recent Advances in Actinide Science covers six main topics: * Analysis, the environment and biotransformations * Coordination and organometallic chemistry * Heavy elements * Nuclear fuels, materials and waste forms * Separations and solution chemistry * Spectroscopy, magnetism and superconductivity Covering a wide range of research from pure academic studies to applied industrial science and technology, this book distils the knowledge and achievements gained in actinide science over the last four years. This high level book is aimed at researchers, both industrial and academic, and provides a comprehensive overview of the current status of actinide science.

The introduction of carbon - fluorine bonds into organic compounds can profoundly influence their chemical and physical properties when compared to their non-fluorine containing analogues, leading to a range of man-made materials with highly desirable properties. These molecules are of interest across the wide spectrum of industrial and academic organic chemistry, from pharmaceuticals, through fine and specialty chemicals to polymers. From Prozac to Teflon, many of the most important products of the chemical and life-science industries rely on organic fluorine chemistry for their useful properties. In this new book the author, internationally known for his contribution to organic fluorine chemistry, covers both the preparative methodologies and chemical properties of partially and highly fluorinated organic systems. Written as an authoritative guide to the subject for organic chemists in universities and the pharmaceutical, agrochemical, specialty organic and polymer industries, the book will also be an important resource for university advanced courses. Dick Chambers is a Fellow of the Royal Society and Emeritus Professor of Chemistry at the University of Durham, Durham, UK.

Structure and Geometry.- Hierarchic structure.- The structure of quasicrystals: from diffraction patterns to atom positions.- Determination of quasi-crystal structures by higher dimensional analysis.- Six-dimensional atoms for a decorated three-dimensional Penrose tiling.- Metrical aspects of quasicrystal embedding in superspace.- Landau theory and direct methods for crystal structures analysis.- Geometry of films of amphiphile molecules: a curved space approach.- Geometrical approach of blue phases.- Electron microscopy and quasicrystals.- On the dark field imaging behaviour of icosahedral phases in rapidly cooled aluminium alloys.- Electron microscopy of modulated structures.- Models for Stability and Growth.- Physical models of perfect quasicrystal growth.- Generation and dynamics of defects in two-dimensional quasicrystals.- Intrinsic stability of quasicrystals and behavior under a load of Frenkel defects.- Reconstructive phase transition to the icosahedral phase.- Structure and growth of twoand three-dimensional hexatic liquid crystals.- The tiling structure of simple liquids: squares and triangles in two dimensions.- Does cholesteric blue phase III have an icosahedral structure ?.- Intrinsic frustration and space curvature in smectic A liquid crystals.- Critical behavior of polymorphic smectic-A liquid crystals.- Universal behavior in phospholipid multimembrane systems.- Pattern formation during the ordering processes in nematic liquid crystals.- Spatially modulated structures in models with competing interactions some new results.- Weakly periodic structures with a singular continuous spectrum.- The Anderson metal-insulator transition: incommensurate versus disordered systems.- Theory of phase transition between two incommensurate phases in NbTe4.- The origin of polytypes in SiC and ZnS.- Structural modulations in the high-temperature superconductor YBa2Cu3O7.? and semi conducting WO3-x, aspects of non-equilibrium behaviour.- Incommensurate modulations in bismuth-based high-Tc superconductors.- Incommensurate commensurate phase transition of Cu2-xTe. (x

In the literature of continuous flow analysis, there are hundreds of descriptions of problems encountered with the various AutoAnalyzer modules. This volume presents the way these have been used in conjunction with chromatographic separations and manufacturing plant process monitoring systems.

High surface area, a microporous structure, and a high degree of surface reactivity make activated carbons versatile adsorbents, particularly effective in the adsorption of organic and inorganic pollutants from aqueous solutions. Activated Carbon Adsorption introduces the parameters and mechanisms involved in the activated carbon adsorption of organic and inorganic compounds. This text brings together the most significant research on surface structure and processes, adsorption theories and isotherm equations, and applications from the latest literature on carbon adsorption. The book clearly explains the surface-related interactions of activated carbons, their energetics, and the applicability of adsorption isotherm equations and their deviation from adsorption data. It then explores numerous applications in a wide range of areas, such as nuclear technology, vacuum technology, food technology, pharmaceuticals and medicine, gas storage, oil refining, and environmental remediation. Topics include: oils and fats, molecular sieves, refining of liquid fuels, pesticides, dyes, drugs, and toxins. Three chapters are dedicated to environmental applications, including the adsorption of halogenated organic compounds and the removal of hazardous gases and vapors, organo-sulphur compounds, and other inorganic compounds from wastewater and groundwater. Activated Carbon Adsorption presents a complete survey of the growing number of state-of-the-art applications supported by a compilation of the latest perspectives in research concerning carbon surfaces and their adsorption processes from aqueous solutions. Its unified approach promotes further research towards improving and developing newer activated carbon adsorbents and processes for the efficient removal of pollutants from drinking water and industrial effluents.

Lately, there has been much interest in the chemistry of Main Group elements with novel compounds being synthesised both in academia and industry. This book examines their synthesis, structure and how they behave chemically.

The second edition follows the same structure as the first except that the biochemistry section has been removed to allow for the inclusion of a wide range of new material. This includes:

• complexation and the stabilization of unstable species;

• new elements and isotopes;

• discussion of, for example, pye-bonding in compounds of the heavier main group elements, electronegativity of F, bonding in sulfur and phosphorus oxo-anions;

• examples of new compounds developed around traditional models; for example, compounds in which multiply-bonded C is replaced by Si and pentavalent organo-derivatives of Group 15

The new edition is aimed at Honors and postgraduate students as well as researchers interested in Main Group elements and their compounds.

On the first edition -

"This is a book I would recommend as background reading for undergraaduates and postgraduates" Education in Chemistry, Chemistry in Britain

"This is a sound and sensible book, coherently produced and well written" The Times Higher Educational Supplement

In the fields of biologically active materials and functional materials, fluorinated organic materials are becoming a focus of significant interest. Over the past decade synthetic methodologies and reagents in fluorine chemistry have been developed, especially stereocontrolled synthetic methods, enzymatic resolution to synthesize enantiomers, fluoromethylated reagents, and fluorination reagents. These methods have contributed to the opening of new pathways for fluorinated materials. However, few fluorinated materials have been put to commercial use. Furthermore, there remain problems to be solved, such as the handling of the materials, availability of reagents and selectivity (stereo-, regio-, and/or chemoselectivity). Research chemists, technical engineers, and graduate students in all branches of chemistry, pharmaceutics, and material science interested in fluorinated materials need to know detailed experimental procedures of how to synthesize the target fluorinated materials. This volume summarizes the chemical and microbial methods for obtaining functionalized fluorinated materials for use as building blocks; detailed experimental methods (reaction conditions, solvent, temperature, handling techniques, etc.); and the stereoview (possible absolute configuration) of the structures with spectral data. Mono-, di-, tri-, and polyfluorinated materials derived from fluorinating agents, fluoromethylated reagents and building blocks are summarized. A chemical name index, molecular formula index, and reagent index are also included. The publication of this monograph will provide access to the enormous possibilities in fluorine chemistry, biological material chemistry, and functionalized material chemistry.

As inorganic materials are put to more and more practical uses--mainly in electric, magnetic, and optical devices--materials scientists must have an increasingly sophisticated understanding of the chemical and physical properties of inorganic compounds. This volume--the first of its kind in twenty years--provides a unified presentation of the chemistry of non-stoichiometric compounds based on statistical thermodynamics and structural inorganic chemistry. Four modern examples of non-stoichiometric compounds--ionic conducting compounds, hydrogen absorbing alloys, magnetic materials, and electrical materials--are discussed in detail. Students and researchers in structural inorganic chemistry, crystallography, materials science, and solid state physics will find this much-needed book both practical and informative.

This book covers one of the most neglected areas in environmental trace analysis, namely that of sample preparation. The text discusses all of the necessary steps for analysing a sample for both trace metals and organics, from the initial sampling protocols, through the range of possible sample preparation methods, and leading finally to the analysis and recording of data. Detailed information is provided on the specific methods to follow for preparing a sample for metal and organic analyses.

The topics covered include the following:

• Basic laboratory skills

• Investigative approaches for sample preparation

• Sampling

• Storage of samples

• Sample preparation for inorganic analysis - solids and liquids

• Sample preparation for organic analysis - solids, liquids and volatile compounds

• Pre-concentration approaches

• Instrumental techniques for trace analysis

• Up-to-date information on the latest developments in sample preparation for metals and organics.

• Written in an open learning/distance learning style, it is ideal for use as a self-study guide or as the basis of a taught course.

• The provision of a comprehensive bibliography to guide the reader to more specialized texts and sources.

Chiral Derivatizing Agents, Macrocycles, Metal Complexes and Liquid Crystals for Enantiomer Differentiation in NMR Spectroscopy: Thomas J. Wenzel. Chiral NMR Solvating Additives for Differentiation of Enantiomers: Gloria Uccello-Barretta and Federica Balzano. Chiral Sensor Devices for Differentiation of Enantiomers: Kyriaki Manoli, Maria Magliulo and Luisa Torsi. Enantiopure supramolecular cages: synthesis and chiral recognition properties: Thierry Brotin, Laure Guy, Alexandre Martinez, Jean-Pierre Dutasta. Interconversion of Stereochemically Labile Enantiomers (Enantiomerization) : Oliver Trapp. Anisotropy Spectra for Enantiomeric Differentiation of Biomolecular Building Blocks: A.C. Evans, C. Meinert, J.H. Bredehoeft, C. Giri, N.C. Jones, S.V. Hoffmann, U.J. Meierhenrich. Self-disproportionation of Enantiomers of Enantiomerically Enriched Compounds: Alexander E. Sorochinsky and Vadim A. Soloshonok.

Designated 'Molecule of the Year' in 1992 in recognition of its many biological roles, nitric oxide has wide significance in the world around us and the story of nitric oxide is still unfolding. This small and seemingly innocent molecule has for many years been known to play a significant role in both the creation of photochemical smogs and in the nitrogen cycle. It has an interesting chemistry as a metal ligand, and the bonding within the nitric oxide molecule has been extensively studied. More recently, the molecule has been in the spotlight for the role it plays in controlling blood flow, in the immune system and in brain activity. Life, Death and Nitric Oxide covers many of the topics relating to nitric oxide, from smog and catalytic converters to tumour growth, blood flow and Viagra, with the aim of finding out why such a simple molecule can do so much.

This book provides a fundamental understanding of the basis of the theoretical treatment of electronic properties in graphite. It illustrates the wide range of topics of interest to researchers on carbon materials and stimulates further understanding of some of the phenomena involved.

This book describes drug metal-ion interactions in the gut and deals with the deficiency of zinc and iron and their pharmacological use. It covers anti-inflammatory activities of copper and gold complexes and considers the role of metal ions and chelating agents in anti-viral chemotherapy.

This concise, easy-to-read book outlines the basic principles needed to understand the chemical mechanisms of explosion. Written for students with no previous knowledge of explosives but some understanding of chemical reactions in mind, it takes the reader through the history of explosives and introduces the concepts of high explosives, propellants and pyrotechnics. Covering combustion, deflagration, and detonation; ignition, initiation, and thermal decomposition; thermochemistry, thermodynamics and kinetics, the text includes detailed formulations and reactions presented with thermochemical calculations to aid understanding. This edition includes environmental legislation and its impact on explosives, together with a section on safety hazard tests. It also contains the latest developments in synthesis and manufacturing of explosives. Covering all aspects of the properties of explosives, The Chemistry of Explosives is a unique text which introduces difficult subjects in a readable manner. Ideal for A-level students and new graduates with no previous knowledge of explosive materials, it will also be useful to anyone needing succinct information on the subject, such as the more experienced chemist in the explosives sector.