Optimal Learning

This new edition of the definitive arc flash reference guide, fully updated to align with the IEEE's updated hazard calculations An arc flash, an electrical breakdown of the resistance of air resulting in an electric arc, can cause substantial damage, fire, injury, or loss of life. Professionals involved in the design, operation, or maintenance of electric power systems require thorough and up-to-date knowledge of arc flash safety and prevention methods. Arc Flash Hazard Analysis and Mitigation is the most comprehensive reference guide available on all aspects of arc flash hazard calculations, protective current technologies, and worker safety in electrical environments. Detailed chapters cover protective relaying, unit protection systems, arc-resistant equipment, arc flash analyses in DC systems, and many more critical topics. Now in its second edition, this industry-standard resource contains fully revised material throughout, including a new chapter on calculation procedures conforming to the latest IEEE Guide 1584 . Updated methodology and equations are complemented by new practical examples and case studies. Expanded topics include risk assessment, electrode configuration, the impact of system grounding, electrical safety in workplaces, and short-circuit currents. Written by a leading authority with more than three decades' experience conducting power system analyses, this invaluable guide: Provides the latest methodologies for flash arc hazard analysis as well practical mitigation techniques, fully aligned with the updated IEEE Guide for Performing Arc-Flash Hazard Calculations Explores an inclusive range of current technologies and strategies for arc flash mitigation Covers calculations of short-circuits, protective relaying, and varied electrical system configurations in industrial power systems Addresses differential relays, arc flash sensing relays, protective relaying coordination, current transformer operation and saturation, and more Includes review questions and references at the end of each chapter Part of the market-leading IEEE Series on Power Engineering, the second edition of Arc Flash Hazard Analysis and Mitigation remains essential reading for all electrical engineers and consulting engineers.

A comprehensive collection of letters spanning the adult life (1914-1973) of one of the world’s most famous storytellers.‘It is not possible even at great length to «pot» The Lord of the Rings in a paragraph or two. It was begun in 1936, and every part has been written many times… the labour has been colossal; and it must stand or fall, practically as it is.’J.R.R. Tolkien was one of the most prolific letter writers of this century. Over the years he wrote to his publishers, his family, to friends (including C.S. Lewis, W.H. Auden and Naomi Mitchison) and to fans of his books. The letters present a fascinating and highly detailed portrait of the man in many of his aspects: as storyteller, scholar, Catholic, parent and observer of the world around him. They also shed much light on his creative genius and grand design for the creation of a whole new world – Middle-earth. This collection will appeal not only to the legions of Tolkien fans, but will entertain anyone who appreciates the art of letter-writing, of which Tolkien was a master.‘I am nearly always written to as Tolkein (not by you): I do not know why, since it is pronounced by me always -keen.’

In the tradition of The Perfect Storm and Into Thin Air, Rachel Slade’s Into the Raging Sea is a nail-biting account of the sinking of the container ship El Faro, the crew of thirty-three who perished onboard, and the destructive forces of globalisation that put the ship in harm’s way.On 1 October 2015, Hurricane Joaquin barreled into the Bermuda Triangle and swallowed the container ship El Faro whole, resulting in one of the worst shipping disasters in decades. No one could fathom how a vessel equipped with satellite communications, a sophisticated navigation system, and cutting-edge weather forecasting could suddenly vanish – until now.Relying on hundreds of exclusive interviews with family members and maritime experts, as well as the words of the crew members themselves – whose conversations were captured by the ship’s data recorder – Rachel Slade unravels the mystery of the sinking of El Faro. As she recounts the final twenty-four hours onboard, Slade vividly depicts the officers’ anguish and fear as they struggled to carry out Captain Michael Davidson’s increasingly bizarre commands, which they knew would steer them straight into the eye of the storm. Taking a hard look at America’s aging merchant marine fleet, Slade also reveals the truth about modern shipping – a cutthroat industry plagued by razor-thin profits and ever more violent hurricanes fueled by global warming.A richly reported account of a singular tragedy, Into the Raging Sea takes us into the heart of an age-old American industry, casting new light on the hardworking crew of El Faro who paid the ultimate price in the name of profit.

Passionate, independent-minded nonfiction from the international bestselling author of ‘The Corrections’.Jonathan Franzen's ‘Freedom’ was the literary sensation of 2010, whilst ‘The Corrections’ was the best-loved and most written-about novel the previous decade. ‘How to be Alone’, is a collection of the personal essays and painstaking, often humorous reportage that have earned Franzen a wide and loyal readership, including what has come to be known as 'The Harper's Essay', Franzen's controversial 1996 look at the fate of the novel. From the sex-advice industry to the way a supermax prison works, from his father's struggle with Alzheimer's disease to a rueful account of Franzen's brief tenure as an Oprah Winfrey author, each piece wrestles with Franzen's familiar themes: the erosion of civic life and private dignity, and the hidden persistence of loneliness, in postmodern imperial America.These collected essays record what Franzen calls 'a movement away from an angry and frightened isolation toward an acceptance – even a celebration – of being a reader and a writer.' They voice a wry distrust of the claims of technology and psychology, the love-hate relationship with consumerism, and the subversive belief in the tragic shape of the individual life that help make Franzen one of the sharpest, toughest-minded, and most entertaining social critics at work today.