scholarly journals Equilibrium Speciation of Select Lanthanides in the Presence of Acidic Ligands in Homo- and Heterogeneous Solutions

2011 ◽  
Author(s):  
Troy A Robinson
Keyword(s):  
Equilibrium Speciation ◽  
Acidic Ligands

Mobility of Chelated Radionuclides in Engineered Concrete Barriers

1992 ◽  
Vol 294 ◽  
Author(s):  
Craig A. Dicke ◽  
Robert W. Smith
Keyword(s):  
Citric Acid ◽  
Chelating Agents ◽  
Ethylenediaminetetraacetic Acid ◽  
Cobalt Complexes ◽  
Alkaline Ph ◽  
Pore Fluids ◽  
Concrete Barriers ◽  
Equilibrium Speciation ◽  
Low Level Radioactive Waste

ABSTRACTConcrete is a major component in many low-level radioactive waste (LLW) disposal facilities. The use of concrete is widespread because of its physical and structural properties and because it provides geochemical control on metal and radionuclide releases. Organic compounds are often disposed with radionuclides in LLW disposal facilities. Interactions between radionuclides and chelating agents must be evaluated to estimate mobility of radionuclides in concrete vaults. This paper quantifies the effects of two common organic components [citric acid and ethylenediaminetetraacetic acid (EDTA)] on radionuclide mobility in concrete barriers by using equilibrium geochemical calculations.Equilibrium speciation calculations indicate that some radionuclides are chelated in groundwater (pH 7) but are destabilized in the highly alkaline (pH 13) concrete pore fluids. Radionuclides complexed by EDTA and citrate are replaced by calcium in the concrete pore fluids. In addition, the citrate nuclide complex reacts to form uncomplexed citrate in concrete pore fluids. The chemical performance of concrete LLW disposal facilities should not be compromised by small amounts of chelating agents disposed with some radionuclides. However, EDTA may form significant nickel and cobalt complexes above the pH important in the long-term service life of concrete barriers.

New Developments in Evolutionary Innovation

2021 ◽  
pp. 1-6
Author(s):  
Gino Cattani ◽  
Mariano Mastrogiorgio
Keyword(s):  
Evolutionary Theory ◽  
Significant Influence ◽  
Evolutionary Biology ◽  
Economic Change ◽  
Evolutionary Process ◽  
Punctuated Equilibrium ◽  
Darwinian Evolution ◽  
New Developments ◽  
Evolutionary Innovation ◽  
Equilibrium Speciation

The publication of ‘An Evolutionary Theory of Economic Change’ by Nelson and Winter has had a major impact on economics and related fields such as innovation and strategy. All of these fields have developed owing to recent re-examinations and extensions of evolutionary theory. A paradigm that underlies several studies in this tradition is the concept of neo-Darwinian evolution—the idea that the unit of the evolutionary process (e.g. a technological artefact) is subject to a dynamic of variation, selection, and retention leading to adaptation to a predefined function. This book refers to the frameworks of punctuated equilibrium, speciation, and exaptation, which, despite their significant influence in evolutionary biology, have been reflected only partially in evolutionary approaches to economics, innovation, and strategy. This chapter introduces the book’s aim to fill this gap, and outlines the approaches and perspectives of each of the chapters.

New Frontiers

2021 ◽  
pp. 7-27
Author(s):  
Gino Cattani ◽  
Mariano Mastrogiorgio
Keyword(s):  
Technological Innovation ◽  
Evolutionary Theory ◽  
Significant Influence ◽  
Evolutionary Biology ◽  
Innovation Process ◽  
Punctuated Equilibrium ◽  
Darwinian Evolution ◽  
Profound Impact ◽  
Equilibrium Speciation

Evolutionary thinking has grown significantly and has had a profound impact on various fields such as economics, strategy, and technological innovation. An important paradigm that underlies the evolutionary theory of innovation is neo-Darwinian evolution. According to this paradigm, evolution is gradualist and is based on the mechanisms of variation, selection, and retention. Starting from the 1970s, new theoretical advancements in evolutionary biology have recognized the central role of punctuated equilibrium, speciation, and exaptation in evolution and of Woesian dynamics. However, despite their significant influence in evolutionary biology, these advancements have been reflected only partially in evolutionary approaches to economics, strategy, and technological innovation. This chapter reviews these advancements and explores their key implications for innovation, such as the role of serendipity and unpre-stateability leading to disequilibrium in economics systems, and the importance of adopting an option-based logic during the innovation process.

scholarly journals Characterization of the ALSEP Process at Equilibrium: Speciation and Stoichiometry of the Extracted Complex

ACS Omega ◽  
2020 ◽  
Vol 5 (14) ◽  
pp. 8076-8089 ◽  
Author(s):  
Gabriela A. Picayo ◽  
Brian D. Etz ◽  
Shubham Vyas ◽  
Mark P. Jensen
Keyword(s):  
Equilibrium Speciation

ChemInform Abstract: The Influence of Alkenes as π-Acidic Ligands in Pd-Catalyzed Cross-Couplings

ChemInform ◽  
2012 ◽  
Vol 43 (5) ◽  
pp. no-no
Author(s):  
Amanda G. Jarvis ◽  
Ian J. S. Fairlamb
Keyword(s):  
Acidic Ligands
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