A spark plug is a device for delivering electric current from an ignition system to the combustion chamber of a spark-ignition engine to ignite the compressed fuel/air mixture by an electric spark, while containing combustion pressure within the engine. A spark plug has a metal threaded shell, electrically isolated from a central electrode by a porcelain insulator; the central electrode, which may contain a resistor, is connected by a insulated wire to the output terminal of an ignition coil or magneto. The spark plug's metal shell is screwed into the engine's cylinder head and thus electrically grounded; the central electrode protrudes through the porcelain insulator into the combustion chamber, forming one or more spark gaps between the inner end of the central electrode and one or more protuberances or structures attached to the inner end of the threaded shell and designated the side, earth, or ground electrode. Spark plugs may be used for other purposes. Spark plugs may be used in other applications such as furnaces wherein a combustible fuel/air mixture must be ignited.

In this case, they are sometimes referred to as flame igniters. In 1860 Étienne Lenoir used an electric spark plug in his gas engine, the first internal combustion piston engine. Lenoir is credited with the invention of the spark plug; some sources credit Edmond Berger, an immigrant from Togo, with creating a spark plug in early 1839, though records show he did not receive a patent for his device. Early patents for spark plugs included those by Nikola Tesla, Frederick Richard Simms and Robert Bosch. Only the invention of the first commercially viable high-voltage spark plug as part of a magneto-based ignition system by Robert Bosch's engineer Gottlob Honold in 1902 made possible the development of the spark-ignition engine. Subsequent manufacturing improvements can be credited to Albert Champion, to the Lodge brothers, sons of Sir Oliver Lodge, who developed and manufactured their father's idea and to Kenelm Lee Guinness, of the Guinness brewing family, who developed the KLG brand. Helen Blair Bartlett played a vital role in making the insulator in 1930.

The plug is connected to the high voltage generated by magneto. As current flows from the coil, a voltage develops between the central and side electrodes. No current can flow because the fuel and air in the gap is an insulator, but as the voltage rises further it begins to change the structure of the gases between the electrodes. Once the voltage exceeds the dielectric strength of the gases, the gases become ionized; the ionized gas allows current to flow across the gap. Spark plugs require voltage of 12,000–25,000 volts or more to "fire" properly, although it can go up to 45,000 volts, they supply higher current during the discharge process, resulting in a hotter and longer-duration spark. As the current of electrons surges across the gap, it raises the temperature of the spark channel to 60,000 K; the intense heat in the spark channel causes the ionized gas to expand quickly, like a small explosion. This is the "click" heard when observing a spark, similar to thunder; the heat and pressure force the gases to react with each other, at the end of the spark event there should be a small ball of fire in the spark gap as the gases burn on their own.

The size of this fireball, or kernel, depends on the exact composition of the mixture between the electrodes and the level of combustion chamber turbulence at the time of the spark. A small kernel will make the engine run as though the ignition timing was retarded, a large one as though the timing was advanced. A spark plug is composed of a shell and the central conductor, it passes through the wall of the combustion chamber and therefore must seal the combustion chamber against high pressures and temperatures without deteriorating over long periods of time and extended use. Spark plugs are specified by size, either thread or nut, sealing type, spark gap. Common thread sizes in Europe are 10 mm, 14 mm, 18 mm. In the United States, common thread sizes are 12 mm, 14 mm and 18 mm; the top of the spark plug contains a terminal to connect to the ignition system. Over of the years variations in the terminal configuration have been introduced by manufacturers; the exact terminal construction varies depending on the use of the spark plug.

Most passenger car spark plug wires snap onto the terminal of the plug, but some wires have eyelet connectors which are fastened onto the plug under a nut. The standard solid non-removable nut SAE configuration is common for many trucks. Plugs which are used for these applications have the end of the terminal serve a double purpose as the nut on a thin threaded shaft so that they can be used for either type of connection; this type of spark plug has a removable nut or knurl, which enables its users to attach them to two different kinds of spark plug boots. Some spark plugs have a bare thread, a common type for motorcycles and ATVs. In recent years, a cup-style terminal has been introduced, which allows for a longer ceramic insulator in the same confined space; the main part of the insulator is made from

Maria Bucur is an American-Romanian historian of modern Eastern Europe and gender in the twentieth century. She has written on the history of eugenics in Eastern Europe and war in twentieth-century Romania and modernism, gender and citizenship, she teaches history and gender studies at Indiana University, where she holds the John W. Hill Professorship. Between 2011 and 2014 she served as founding Associate Dean of the School of Global and International Studies and helped inaugurate the first SGIS graduating class in 2014. After attending Georgetown University as an undergraduate in the School of Foreign Service and spending a year at the School for Slavonic and East European Studies in London, she obtained graduate degrees in history from the University of Illinois, Urbana-Champaign. There she worked under the guidance of Sonya Michel, she has been working at Indiana University, since 1996, where she holds the John W. Hill Chair in East European History. Since 2016 she has been a professor of Gender Studies.

At Indiana University she served as Chair of Gender Studies, Director of the Russian and East European Institute, Co-Director of the European Union Center for Excellence, founding Associate Dean of the School of Global and International Studies. She has worked for several publications: Associate Editor of the American Historical Review, Co-Editor for the Aspasia Yearbook of Gender and Women's History, Board member for Gender and History, Journal of Women's History, Archiva Moldaviae, Cogent Arts and Humanities, Integru.org. She has served as President of the Association for Women in Slavic Studies, as Coordinator of the Gender and Women’s History Network for the European Social Science History Conference, as Chair of the Committee on Women Historians for the American Historical Association. In addition, she has served on the General Council as well as the History Committee of the National Council for Accreditation of University Titles and Certificates, Ministry of Education and Research, Romania.

Bucur has published eight volumes, three of them as a single author, the rest as co-author or editor. Her first monograph and Modernization in Interwar Romania, examined the intellectual debates and policy-making activities of a group of doctors, biologists and politicians who used eugenicist ideas to propel Romanian society and institutions to a level of modernization in social engineering akin to attempts made in Germany and other West European states during the same period, her second monograph and Victims: Remembering War in Twentieth-Century Romania, offered a close examination of various forms of remembering and commemorating the two world wars from 1918 onwards, with a focus on the tensions between grassroots and individual efforts and state-initiated commemorations. With a focus on the different meanings embodied in these various efforts, Bucur illuminates the important role played by such contestations in shaping the meaning of heroism and self-sacrifice along gender and ethno-religious lines.

More she has published Gendering Modernism: A Historical Reappraisal of the Canon, which asks readers to reconsider the revolutionary aspects of modernism from the perspective gender norms. In 2018 she is publishing two new books; the Century of Women: How Women Have Transformed the World Since 1900 is a bold overview of recent history from a feminist humanist perspective, placing women's historical empowerment at the heart of understanding recent changes in politics, demography and knowledge making. Karen Offen, of Stanford University, calls it a book that "should find a place on every intelligent person's reading list." Her newest monograph, co-authored with Mihaela Miroiu, Birth of Democratic Citizenship: Women in Modern Romania, will come out in November 2018 with Indiana University Press. In addition to these monographs and other co-edited volumes, she has published over seventy articles and chapters in a variety of outlets, from The American Historical Review to the Times Literary Supplement.

She has had dozens of media appearances and interviews in the press, from the History Channel to Al-Jazeera. A passionate promoter of culture and history from her native country, Bucur has helped organize eleven conferences on Romanian Studies at Indiana University. Together with her colleague Christina Zarifopol-Illias, she worked to establish the first Romanian Studies graduate fellowship in the United States at Indiana University, she has worked with various partners in Romania. At Babeș-Bolyai University in Cluj-Napoca, together with a team of scholars from Indiana University and the Central European University, she helped launch the Oral History Center in 1997, she has worked with colleagues at the National School for Political Science and Public Administration in Bucharest on a several research and publication projects, taught several graduate workshops. She has collaborated with Transylvania University in Brașov and the Aspera foundation on two oral history workshops. In addition to these academic events, she has worked with artists and musicians to promote visibility for Romanian culture.

Bucur is the recipient of numerous grants and fellowships, among them two National Endowments for the Humanities research grants, a research fellowship from the Woodrow Wilson Center in Washington, DC, a fellowship from the American Associat

Everybody's Talkin' is the second album and the first live album by the 11-piece Tedeschi Trucks Band and was released in 2012 by Sony Masterworks. It's been released as a 2-CD set as well as a three disc vinyl set; the title comes from the song carrying the same name a hit for Harry Nilsson. The band's cover is a hybrid of the Bill Withers versions; the songs on the album are a compilation of recordings from the following three nights October 25, 2011 at The Danforth Music Hall, Toronto, ON by Embrace Presents October 28, 2011 at the Warner Theatre, Washington, D. C. October 29, 2011 at Fairfield Theatre Compagny at The Klein, Bridgeport, CTIn an interview with Rolling Stone magazine, Trucks stated many of the tracks came from the almost-cancelled Bridgeport, CT show. "There was a real loose feeling to it. We used a lot of stuff from that night." Writing for Allmusic, critic Thom Jurek wrote "It's an unusual live record because its balance of sonic precision and stage-born kinetics is perfect—this band transitions seamlessly between R&B, rock and jazz.

These performances never succumb to mere jam band clichés... Everybody's Talkin' is what every live album should be: an accurate, exciting reflection of a hot band playing full-throttle." He praised Tedeschi as "among the great singers in modern blues and rock. Will Layman of PopMatters praised the performances and called it "the kind of music that shamelessly moves at you with emotion and soul". Doug Collette of All About Jazz praised the album the sound, but was critical of the length of the songs, commenting on the "shortage of instrumental fireworks"; the review aggregator site, Metacritic calculated an average score of 75 based on 6 reviews. Derek Trucks – lead guitar Susan Tedeschi – lead vocals, rhythm guitar Oteil Burbridge – bass guitar Kofi Burbridge – keyboards, flute Tyler Greenwell – drums, percussion J. J. Johnson – drums, percussion Mike Mattison – harmony vocals Mark Rivers – harmony vocals Kebbi Williams – saxophone Maurice "Mobetta" Brown – trumpet Saunders Sermons – trombone Producers - Derek Trucks Engineers - Bobby Tis Additional Engineer - Marty Wall Mixing - Jim Scott Mastering - Bob Ludwig