Element 43—Technetium

2013 ◽  
Author(s):  
Eric Scerri
Keyword(s):  
Hydrogen Peroxide ◽  
Twentieth Century ◽  
Sodium Hydroxide ◽  
Empty Space ◽  
Atomic Weight ◽  
P Element ◽  
Chemical Analyses ◽  
New Members ◽  
The World ◽  
Emilio Segrè

Element 43 (fig. 6.1) holds a special distinction among the seven elements of this book. It was one of just four elements that Mendeleev first predicted in his famous table and article of 1871. This fact is not so well known, as most accounts mention just the three famous predictions, namely empty spaces to which Mendeleev gave atomic weights of 44, 68, and 72. These three elements were all discovered within a period of fifteen years and named scandium, gallium, and germanium, respectively. But in the same early table, Mendeleev assigned an atomic weight to just one more empty space, which he placed below manganese. Mendeleev predicted that it would have an atomic weight of 100, although he changed it slightly to 99 in his book, The Principles of Chemistry . Given the success of Mendeleev’s first three predictions it is hardly surprising that strenuous efforts were made, in many parts of the world, to find the fourth element. Little did these early chemists know the problems they would encounter in trying to isolate this particularly rare and unstable element. In the early twentieth century, several claims were made for the discovery of the element. But these alleged elements, given various names such as davyum, illenium, lucium, and nipponium all turned out to be spurious. Then, in 1925, as mentioned in the last chapter, Otto Berg, Walter Noddack, and Ida Tacke (later Ida Noddack), claimed to have discovered not just one but two new members of group 7, which they named masurium and rhenium. Although their discovery of rhenium was accepted, their claim for the element directly below manganese has been bitterly disputed ever since. The official discovery of element 43 is accorded to Emilio Segrè and coworkers. Technetium, as they eventually called it, had to be synthesized rather than isolated from naturally occurring sources. It is also the only element to ever be “discovered” in Italy—in Palermo, Sicily, to be more precise. Segrè , who had been a visitor at the Berkeley cyclotron facility in California, was sent some molybdenum plates that had been irradiated for several months with a deuterium beam. Various chemical analyses by the Italian team revealed a new element, which could be extracted by boiling with sodium hydroxide that also contained a small amount of hydrogen peroxide.

Development of the Jewish religious movement "Khabad" in Ukraine in the 20's of the twentieth century

2001 ◽  
pp. 85-90
Author(s):  
O. V. Kozerod
Keyword(s):  
Twentieth Century ◽  
Religious Movement ◽  
Important Research ◽  
The World ◽  
Research Problems

The development of the Jewish religious movement "Khabad" and its organizations in the first quarter of the twentieth century - one of the important research problems, which is still practically not considered in the domestic Judaica. At the same time, this problem is relevant in connection with the fact that the religious movement "Khabad" during the twentieth century became the most widespread and influential area of Judaism in Ukraine and throughout the world.

Bleaching optimization at WestRock mill in Covington, Virginia

TAPPI Journal ◽  
2016 ◽  
Vol 15 (9) ◽  
pp. 581-586 ◽  
Author(s):  
RICARDO B. SANTOS ◽  
PETER W. HART ◽  
DOUGLAS C. PRYKE ◽  
JOHN VANDERHEIDE
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hydroxide ◽  
Chlorine Dioxide ◽  
Capital Expenditures ◽  
Equipment Repair ◽  
Optimization Program ◽  
Hardwood Pulp ◽  
Improved Performance

The WestRock mill in Covington, VA, USA, initiated a long term diagnostic and optimization program for all three of its bleaching lines. Benchmarking studies were used to help identify optimization opportunities. Capital expenditures for mixing improvement, filtrate changes, equipment repair, other equipment changes, and species changes were outside the scope of this work. This focus of this paper is the B line, producing southern hardwood pulp in a D(EP)DD sequence at 88% GE brightness. The benchmarking study and optimization work identified the following opportunities for improved performance: nonoptimal addition of caustic and hydrogen peroxide to the (EP) stage, carryover of D0 filtrate to the (EP) stage, and carryover of (EP) filtrate to the D1 stage. As a result of actions the mill undertook to address these opportunities, D0 kappa factor decreased about 5%, sodium hydroxide consumption in the (EP) stage decreased about 35%, chlorine dioxide consumption in the D1 stage decreased about 25%, and overall bleaching cost decreased about 15%.

Coda: The Rosetta Stone

2018 ◽  
Author(s):  
Jesse Schotter
Keyword(s):  
Twentieth Century ◽  
New Media ◽  
Digital Media ◽  
The Novel ◽  
Digital Code ◽  
Media Technologies ◽  
Rosetta Stone ◽  
The World ◽  
Western Imagination ◽  
Origin Point

Hieroglyphs have persisted for so long in the Western imagination because of the malleability of their metaphorical meanings. Emblems of readability and unreadability, universality and difference, writing and film, writing and digital media, hieroglyphs serve to encompass many of the central tensions in understandings of race, nation, language and media in the twentieth century. For Pound and Lindsay, they served as inspirations for a more direct and universal form of writing; for Woolf, as a way of treating the new medium of film and our perceptions of the world as a kind of language. For Conrad and Welles, they embodied the hybridity of writing or the images of film; for al-Hakim and Mahfouz, the persistence of links between ancient Pharaonic civilisation and a newly independent Egypt. For Joyce, hieroglyphs symbolised the origin point for the world’s cultures and nations; for Pynchon, the connection between digital code and the novel. In their modernist interpretations and applications, hieroglyphs bring together writing and new media technologies, language and the material world, and all the nations and languages of the globe....

Modernism, Empiricism, and Rationalism

2016 ◽  
Vol 46 (1) ◽  
pp. 38-47
Author(s):  
Geoffrey Squires
Keyword(s):  
Twentieth Century ◽  
The Other ◽  
Modern Poetry ◽  
Philosophical Perspective ◽  
Irish Poetry ◽  
Dimensional Spectrum ◽  
Culture History ◽  
The World ◽  
The Impact ◽  
Rule Out

Modernism is usually defined historically as the composite movement at the beginning of the twentieth century which led to a radical break with what had gone before in literature and the other arts. Given the problems of the continuing use of the concept to cover subsequent writing, this essay proposes an alternative, philosophical perspective which explores the impact of rationalism (what we bring to the world) on the prevailing empiricism (what we take from the world) of modern poetry, which leads to a concern with consciousness rather than experience. This in turn involves a re-conceptualisation of the lyric or narrative I, of language itself as a phenomenon, and of other poetic themes such as nature, culture, history, and art. Against the background of the dominant empiricism of modern Irish poetry as presented in Crotty's anthology, the essay explores these ideas in terms of a small number of poets who may be considered modernist in various ways. This does not rule out modernist elements in some other poets and the initial distinction between a poetics of experience and one of consciousness is better seen as a multi-dimensional spectrum that requires further, more detailed analysis than is possible here.

Hard Objects in George Oppen's Discrete Series

2018 ◽  
Vol 13 (4) ◽  
pp. 496-517
Author(s):  
Ned Hercock
Keyword(s):  
Twentieth Century ◽  
Ludwig Wittgenstein ◽  
Discrete Series ◽  
Human Experience ◽  
John Ruskin ◽  
Gerard Manley Hopkins ◽  
Marcel Duchamp ◽  
The World ◽  
Production History ◽  
History Of

This essay examines the objects in George Oppen's Discrete Series (1934). It considers their primary property to be their hardness – many of them have distinctively uniform and impenetrable surfaces. This hardness and uniformity is contrasted with 19th century organicism (Gerard Manley Hopkins and John Ruskin). Taking my cue from Kirsten Blythe Painter I show how in their work with hard objects these poems participate within a wider cultural and philosophical turn towards hardness in the early twentieth century (Marcel Duchamp, Adolf Loos, Ludwig Wittgenstein and others). I describe the thinking these poems do with regard to industrialization and to human experience of a resolutely object world – I argue that the presentation of these objects bears witness to the production history of the type of objects which in this era are becoming preponderant in parts of the world. Finally, I suggest that the objects’ impenetrability offers a kind of anti-aesthetic relief: perception without conception. If ‘philosophy recognizes the Concept in everything’ it is still possible, these poems show, to experience resistance to this imperious process of conceptualization. Within thinking objects (poems) these are objects which do not think.

On Metaphysics and the Political: A Polemics of Reading Baudelaire in the 1930s

2019 ◽  
Vol 58 (2) ◽  
pp. 249-259
Author(s):  
Joseph Acquisto
Keyword(s):  
Twentieth Century ◽  
Political Crisis ◽  
The Political ◽  
Modern Poetry ◽  
Progressive Politics ◽  
The World ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

This essay examines a polemic between two Baudelaire critics of the 1930s, Jean Cassou and Benjamin Fondane, which centered on the relationship of poetry to progressive politics and metaphysics. I argue that a return to Baudelaire's poetry can yield insight into what seems like an impasse in Cassou and Fondane. Baudelaire provides the possibility of realigning metaphysics and politics so that poetry has the potential to become the space in which we can begin to think the two of them together, as opposed to seeing them in unresolvable tension. Or rather, the tension that Baudelaire animates between the two allows us a new way of thinking about the role of esthetics in moments of political crisis. We can in some ways see Baudelaire as responding, avant la lettre, to two of his early twentieth-century readers who correctly perceived his work as the space that breathes a new urgency into the questions of how modern poetry relates to the world from which it springs and in which it intervenes.

Features of the development of an unmanned rocket-culture technology in the first half of the twentieth century

2018 ◽  
pp. 135-144
Author(s):  
O. O. Gubka
Keyword(s):  
Twentieth Century ◽  
Subsequent Formation ◽  
Technical Schools ◽  
Space Industry ◽  
The World ◽  
Culture Technology

The features of unmanned rocket and space engineering´s development in the USSR and in the world in the first half of the XX century were considered in the article. They defined subsequent formation of scientific and technical schools in the rocket and space industry.

Aftershocks

2017 ◽  
Author(s):  
Seva Gunitsky
Keyword(s):  
Twentieth Century ◽  
Regime Change ◽  
International System ◽  
Political Legitimacy ◽  
Great Powers ◽  
Past Century ◽  
The Past ◽  
Sudden Rise ◽  
The World ◽  
National Borders

Over the past century, democracy spread around the world in turbulent bursts of change, sweeping across national borders in dramatic cascades of revolution and reform. This book offers a new global-oriented explanation for this wavelike spread and retreat—not only of democracy but also of its twentieth-century rivals, fascism, and communism. The book argues that waves of regime change are driven by the aftermath of cataclysmic disruptions to the international system. These hegemonic shocks, marked by the sudden rise and fall of great powers, have been essential and often-neglected drivers of domestic transformations. Though rare and fleeting, they not only repeatedly alter the global hierarchy of powerful states but also create unique and powerful opportunities for sweeping national reforms—by triggering military impositions, swiftly changing the incentives of domestic actors, or transforming the basis of political legitimacy itself. As a result, the evolution of modern regimes cannot be fully understood without examining the consequences of clashes between great powers, which repeatedly—and often unsuccessfully—sought to cajole, inspire, and intimidate other states into joining their camps.

Chemical analyses in the World Coal Quality Inventory

2010 ◽  
Author(s):  
Susan J. Tewalt ◽  
Harvey E. Belkin ◽  
John R. SanFilipo ◽  
Matthew D. Merrill ◽  
Curtis A. Palmer ◽  
...  
Keyword(s):  
Chemical Analyses ◽  
Coal Quality ◽  
The World

A war hero or a Hitler soldier?

2019 ◽  
pp. 50-57
Author(s):  
Pavel Gotovetsky
Keyword(s):  
Twentieth Century ◽  
World War Ii ◽  
Interwar Period ◽  
Military Service ◽  
Third Reich ◽  
National Committee ◽  
World War ◽  
The Third ◽  
The World ◽  
The Third Reich

The article is devoted to the biography of General Pavlo Shandruk, an Ukrainian officer who served as a Polish contract officer in the interwar period and at the beginning of the World War II, and in 1945 became the organizer and commander of the Ukrainian National Army fighting alongside the Third Reich in the last months of the war. The author focuses on the symbolic event of 1961, which was the decoration of General Shandruk with the highest Polish (émigré) military decoration – the Virtuti Militari order, for his heroic military service in 1939. By describing the controversy and emotions among Poles and Ukrainians, which accompanied the award of the former Hitler's soldier, the author tries to answer the question of how the General Shandruk’s activities should be assessed in the perspective of the uneasy Twentieth-Century Polish-Ukrainian relations. Keywords: Pavlo Shandruk, Władysław Anders, Virtuti Militari, Ukrainian National Army, Ukrainian National Committee, contract officer.

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