Even in the 21st Century, the manufacture of leather retains an air of the dark arts, still somewhat shrouded in the mysteries of a millennia old, craft based industry. Despite the best efforts of a few scientists over the last century or so, much of the understanding of the principles of tanning is still based on received wisdom and experience. Leather is made from (usually) the hides and skins of animals - large animals such as cattle have hides, small animals such as sheep have skins. The skin of any animal is largely composed of the protein collagen, so it is the chemistry of this fibrous protein and the properties it confers to the skin with which the tanner is most concerned. In addition, other components of the skin impact on processing, impact on the chemistry of the material and impact on the properties of the product, leather. Therefore, it is useful to understand the relationships between skin structure at the molecular and macro levels, the changes imposed by modifying the chemistry of the material and the eventual properties of the leather. This book aims to contribute to changing the thinking in the industry, to continue building a body of scientific understanding, aimed at enhancing the sustainability of an industry which produces a unique group of materials, derived from a natural source. The Science of Leather is the only current text on tanning science, and addresses the scientific principles which underpin the processes involved in making leather. It is concerned with the chemical modification of collagen, prior to tanning and the tanning reactions in particular. The subject is covered in the following order: collagen chemistry, collagen structure, skin structure, processing to prepare for tanning, the tanning processes and processing after tanning. The aim of the book is to provide leather scientists and technologists with an understanding of how the reactions work, the nature of their outcomes and how the processes can be controlled and changed. The objective is to synthesise a scientific view of leather making and to arrive at an understanding of the nature of tanning - how the wide range of chemistries employed in the art can change the properties of collagen, making leather with different properties, especially conferring different degrees of stabilisation as measured by the hydrothermal stability. Environmental issues are not treated as a separate theme - the impact of leather making on the environment is a thread running through the text, with the assumption that better understanding of the science of leather making will lead to improved processing. The book also reflects on the ways leather technology may develop in the future based on the foundation of understanding the scientific principles which can be exploited. It also includes a subject index, references and a glossary. The book provides the reader with insights into the role science plays in leather technology and provides fundamental understanding, which should be the basis for scientific and technological research and development for the benefit of the global leather industry. The book is aimed at students, leather scientists and technologists, in both academia and industry, in leather production and in chemical supply houses.
This book offers a state-of-the-art view of leather making, based on the scientific principles underpinning the technology. In particular, it contributes to the understanding of the modern leather industry, allowing practitioners to make judgements about day-to-day problems in the tannery and how change can be applied in a predictable way. Major themes running through the book are the economics and environmental impact of leather making and how these will ensure the sustainability of the industry. This second edition of Tony Covington’s Tanning Chemistry is a revision, update and extension in collaboration with a new co-author, Will Wise. The update reflects the advances made in the past decade, including a discussion of the impact of new information concerning the chemistry of sulfide. The original chapters have been re-organised and new chapters on novel modes of reagent delivery and the principles of finishing are now included. Enzymology is addressed as a separate topic, as are environmental impact and the future of leather. The book will be useful to all those involved in the supply chain, from farm, through students, chemical suppliers and tanners, to leather goods brands. Leather science is the key to understanding leather technology, to make it work, to make it work better and to keep it ahead of the competition.
Even in the 21st Century, the manufacture of leather retains an air of the dark arts, still somewhat shrouded in the mysteries of a millennia old, craft based industry. Despite the best efforts of a few scientists over the last century or so, much of the understanding of the principles of tanning is still based on received wisdom and experience. Leather is made from (usually) the hides and skins of animals - large animals such as cattle have hides, small animals such as sheep have skins. The skin of any animal is largely composed of the protein collagen, so it is the chemistry of this fibrous protein and the properties it confers to the skin with which the tanner is most concerned. In addition, other components of the skin impact on processing, impact on the chemistry of the material and impact on the properties of the product, leather. Therefore, it is useful to understand the relationships between skin structure at the molecular and macro levels, the changes imposed by modifying the chemistry of the material and the eventual properties of the leather. This book aims to contribute to changing the thinking in the industry, to continue building a body of scientific understanding, aimed at enhancing the sustainability of an industry which produces a unique group of materials, derived from a natural source. The Science of Leather is the only current text on tanning science, and addresses the scientific principles which underpin the processes involved in making leather. It is concerned with the chemical modification of collagen, prior to tanning and the tanning reactions in particular. The subject is covered in the following order: collagen chemistry, collagen structure, skin structure, processing to prepare for tanning, the tanning processes and processing after tanning. The aim of the book is to provide leather scientists and technologists with an understanding of how the reactions work, the nature of their outcomes and how the processes can be controlled and changed. The objective is to synthesise a scientific view of leather making and to arrive at an understanding of the nature of tanning - how the wide range of chemistries employed in the art can change the properties of collagen, making leather with different properties, especially conferring different degrees of stabilisation as measured by the hydrothermal stability. Environmental issues are not treated as a separate theme - the impact of leather making on the environment is a thread running through the text, with the assumption that better understanding of the science of leather making will lead to improved processing. The book also reflects on the ways leather technology may develop in the future based on the foundation of understanding the scientific principles which can be exploited. It also includes a subject index, references and a glossary. The book provides the reader with insights into the role science plays in leather technology and provides fundamental understanding, which should be the basis for scientific and technological research and development for the benefit of the global leather industry. The book is aimed at students, leather scientists and technologists, in both academia and industry, in leather production and in chemical supply houses.
An encounter at the Million Man March sucks Gunner into an ice-cold missing persons case Elroy Covington should have run. He had traveled to the Million Man March in Washington, DC, looking forward to a new city and new faces. Then in a Dupont Circle restaurant, a twist of fate brought him face to face with a man from his long-forgotten past. Instead of running, Elroy said hello. He never made it home. Eight months later, Elroy’s sister shows up in the Los Angeles office of private detective Aaron Gunner, who traded business cards with Elroy at the march and promptly forgot they ever met. Elroy’s last known location was Los Angeles, and his sister thinks he was coming to see the detective. As he tries to warm up Elroy’s frigid trail, Gunner uncovers ties to a black militant group. The time for brotherhood is over, and finding the vanished marcher will mean getting tough.
DIVWhen his ex-fiancée is murdered, Gunner vows to take vengeance on Los Angeles/divDIV/divDIVFor more than a decade, private detective Aaron Gunner has regretted letting Nina Hillman go. They met on a city bus while he was on his way to the Los Angeles Coliseum for a football game, and by the time they were through talking he had long since missed kickoff. He proposed to her quickly, only to get cold feet and cancel the wedding. After less than a year, she married another man. Eleven years later, Gunner is still alone, and Nina’s house is a crime scene./divDIV /divDIVThe homicide detectives tell Gunner that Nina’s husband has been abusing her for years. They assume that today he simply went too far. As he seeks justice for his long-lost love, Gunner uncovers a citywide chain of domestic abuse that he could have saved Nina from, had he been man enough to marry her. It’s too late to protect her now. Revenge will have to do./div
During World War II, the air over the continental United States was a virtual third front. The little-known statistics are alarming: the Army Air Forces lost more than 4,500 aircraft in combat against Japanese army and naval air forces in the war. During the same time, the AAF lost more than 7,100 aircraft in the United States to accidents in training and transportation. Such accidents claimed the lives of more than 15,530 pilots, crewmembers and ground personnel, and the stories of their deaths are largely forgotten. This work chronicles the 6,350 known fatal AAF aircraft accidents that occurred in the continental United States from January 1941 through December 1945. Each crash summary, based on official records, provides details such as crash location and cause, the people involved and the type and number of aircraft. An aircraft serial number index, a record of AAF aircraft still listed as missing, crash statistics and a directory of AAF stations in the United States are included.
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