Complexation and Redox Chemistry of Neptunium, Plutonium and Americium with a Hydroxylaminato Ligand

Silicon-On-Insulator (SOI) technology [1-4] has been shown to have significant performance and fabrication advantages over conventional bulk processing for a wide variety of large scale CMOS IC applications. Advantages in radiation environments has generated significant interest in this technology from military and space science communities [5,6]. Possible advantages of SOI technology for low power, low voltage and high performance circuit applications is under serious consideration by several commercial IC manufacturers [7,8].

Download Full-text

Physicochemical exfoliation of graphene sheets using graphitic carbon nitride

New Journal of Chemistry ◽

10.1039/c9nj02149c ◽

2019 ◽

Vol 43 (41) ◽

pp. 16200-16206 ◽

Cited By ~ 2

Author(s):

V. Priyanka ◽

G. Savithiri ◽

R. Subadevi ◽

V. Suryanarayanan ◽

M. Sivakumar

Keyword(s):

Large Scale ◽

Carbon Nitride ◽

Graphitic Carbon ◽

Graphitic Carbon Nitride ◽

Graphene Sheets ◽

Toxic Materials ◽

Significant Interest

The development of methods for the synthesis of graphene on a large scale at an affordable cost using less toxic materials has attracted significant interest in recent years.

Download Full-text

Flow Battery Electroanalysis 2: Influence of Surface Pretreatment on Fe(III/II) Redox Chemistry at Carbon Electrodes

10.26434/chemrxiv.7125107.v1 ◽

2018 ◽

Author(s):

Tejal Sawant ◽

James McKone

Keyword(s):

Electron Transfer ◽

Photoelectron Spectroscopy ◽

Large Scale ◽

Redox Chemistry ◽

Rotating Disk Electrode ◽

Electrochemical Activation ◽

Carbon Electrodes ◽

Electron Transfer Kinetics ◽

Treatment Protocols ◽

Flow Batteries

Redox flow batteries are attractive for large-scale electrochemical energy storage, but sluggish electron transfer kinetics often limit their overall energy conversion efficiencies. In an effort to improve our understanding of these kinetic limitations in transition metal based flow batteries, we used rotating-disk electrode voltammetry to characterize the electron-transfer rates of the Fe3+/2+ redox couple at glassy carbon electrodes whose surfaces were modified using several pre-treatment protocols. We found that surface activation by electrochemical cycling in H2SO4(aq) electrolyte resulted in the fastest electron-transfer kinetics: j0 = 0:90 mA/cm2 in an electrolyte containing 10 mM total Fe. By contrast, electrodes that were chemically treated to either remove or promote surface oxidation yielded rates that were at least an order of magnitude slower: j0 = 0:07 and 0:08 mA/cm2, respectively. By correlating these findings with X-ray photoelectron spectroscopy data, we conclude that Fe3+/2+ redox chemistry is catalyzed by carbonyl groups whose surface concentrations are increased by electrochemical activation.

Download Full-text

Two-step pathway for isoprenoid synthesis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1812935116 ◽

2018 ◽

Vol 116 (2) ◽

pp. 506-511 ◽

Cited By ~ 36

Author(s):

Alkiviadis Orfefs Chatzivasileiou ◽

Valerie Ward ◽

Steven McBride Edgar ◽

Gregory Stephanopoulos

Keyword(s):

Glucose Metabolism ◽

Large Scale ◽

Scale Production ◽

Isopentenyl Diphosphate ◽

Dimethylallyl Diphosphate ◽

Large Scale Production ◽

Significant Interest ◽

Complex Regulation ◽

Almost All ◽

Utilization Pathway

Isoprenoids comprise a large class of chemicals of significant interest due to their diverse properties. Biological production of isoprenoids is considered to be the most efficient way for their large-scale production. Isoprenoid biosynthesis has thus far been dependent on pathways inextricably linked to glucose metabolism. These pathways suffer from inherent limitations due to their length, complex regulation, and extensive cofactor requirements. Here, we present a synthetic isoprenoid pathway that aims to overcome these limitations. This isopentenol utilization pathway (IUP) can produce isopentenyl diphosphate or dimethylallyl diphosphate, the main precursors to isoprenoid synthesis, through sequential phosphorylation of isopentenol isomers isoprenol or prenol. After identifying suitable enzymes and constructing the pathway, we attempted to probe the limits of the IUP for producing various isoprenoid downstream products. The IUP flux exceeded the capacity of almost all downstream pathways tested and was competitive with the highest isoprenoid fluxes reported.

Download Full-text

Actinide binding by Kläui ligands: REDOX speciation and sorption on an extraction chromatography resin

Radiochimica Acta ◽

10.1524/ract.2008.1524 ◽

2008 ◽

Vol 96 (12) ◽

Cited By ~ 3

Author(s):

Tatiana G. Levitskaia ◽

Sergey I. Sinkov ◽

Gregg J. Lumetta

Keyword(s):

Extraction Chromatography ◽

Redox Reactions ◽

Oxidation States ◽

Sorption Behavior ◽

Acid Solutions ◽

Methyl Derivative ◽

Acid Base ◽

High Affinity ◽

Nitric Acid Solutions ◽

Actinide Ions

AbstractThe sorption of Eu(III) and actinide ions in various oxidation states from nitric acid solutions by an extraction chromatography resin containing 1 wt. % of the Kläui ligand CpResin samples loaded with various actinide ions were examined spectrophotometrically. No Np(V) and Pu(III) species were identified on the resin; rather, reduction–oxidation (REDOX) reactions occurred during equilibration, resulting in their complete conversion to M(IV) species bound by the Kläui ligand. Similarly, the sorption behavior of Pu(VI) and Np(VI) was complicated by their reduction to M(IV) upon sorption. The observed REDOX processes were apparently driven by the extremely high affinity of the Kläui ligand for the tetravalent ions. The acid–base properties of the methyl derivative of the Kläui ligand were investigated in aqueous solution, and its p

Download Full-text

Development and Optimization of Zirconium-89 Production and Clinical TF-PET/CT Imaging Protocols for Breast Tumor Imaging and Immunotherapy Planning: A Review

Journal of Medical Imaging and Health Informatics ◽

10.1166/jmihi.2019.2526 ◽

2019 ◽

Vol 9 (2) ◽

pp. 215-222

Author(s):

Khalid Alzimami

Keyword(s):

Pet Imaging ◽

Large Scale ◽

Tumor Imaging ◽

Scale Production ◽

Imaging Protocols ◽

Positron Emission ◽

Large Scale Production ◽

Pet Ct ◽

Significant Interest ◽

Potential Use

Zirconium-89 (89Zr) has recently drawn significant interest to be a promising metallo-radionuclide for use in immuno-PET due to favorable decay characteristics. Despite all efforts that have been done over the last few years in the development of procedures for large-scale production and purification of 89Zr and its stable coupling to mAbs as well as successful preclinical and clinical 89Zr immuno-positron emission tomography (PET) studies, there is still gap for exploring new peptide-based pharmaceuticals radiolabeled with 89Zr and the development of 89Zr immuno-PET imaging protocols. The objectives of this study is intended to review the recent development and optimization of 89Zr production and to discuss the 89Zr immuno-PET clinical imaging applications for breast cancer. In addition, the 89Zr PET imaging safety and protocols as well as the potential use of 89Zr in 3-gamma PET Imaging are reviewed.

Download Full-text

Large-Scale Synthesis of Aniline Trimers in Different Oxidation States

Synthesis ◽

10.1055/s-0037-1611889 ◽

2019 ◽

Vol 51 (19) ◽

pp. 3611-3616

Author(s):

Gerardo Yepez ◽

Anurag Noonikara Poyil ◽

Alejandro Bugarin

Keyword(s):

Organic Compounds ◽

Large Scale ◽

Oxidation States ◽

Important Class ◽

Large Scale Synthesis ◽

Synthetic Approaches ◽

First Time

Polyanilines are an important class of organic compounds, due to their utility in a large variety of applications. In contrast, oligoanilines have been employed far more sporadically, in large part reflecting an absence of refined synthetic approaches. Herein, we report, for the first time, a relatively large-scale strategy to generate highly pure aniline trimers at different oxidation states with excellent yields (90–97%).

Download Full-text

Aquatic chemistry and solubility phenomena of actinide oxides/hydroxides

Pure and Applied Chemistry ◽

10.1351/pac200274101895 ◽

2002 ◽

Vol 74 (10) ◽

pp. 1895-1907 ◽

Cited By ~ 87

Author(s):

Thomas Fanghänel ◽

V. Neck

Keyword(s):

Oxidation States ◽

Crystalline Solids ◽

Solubility Behavior ◽

Hydrous Oxides ◽

Long Time ◽

Experimental Solubility Data ◽

Actinide Oxides ◽

Effect Of Particle Size ◽

Colloid Formation ◽

Actinide Ions

The present paper gives an overview of the solubility behavior of actinide oxides/hydroxides, taking into account hydrolysis reactions up to colloid formation. The analogies, systematic trends, and differences in the hydrolysis and solubility constants of actinides in the oxidation states An(III) to An(VI) correlate with the charge and size of the actinide ions. The formation of amorphous and crystalline solids and the discrepancies between the corresponding experimental solubility data may be explained as an effect of particle size. However, using thermodynamic data for the stable crystalline solids, the predicted solubilities are often significantly lower than experimental data (even in long-time experiments), indicating that the solubility is controlled by the surface properties. Typical examples are the known U(VI) solids schoepite and sodium diuranate. The most striking example is provided by the tetravalent actinides. Above the threshold of hydrolysis, the dissolution of microcrystalline or crystalline An(IV) oxides is found to be irreversible. The measured concentrations approach those of the amorphous hydroxides or hydrous oxides.

Download Full-text

Tsunami loading of near-shoreline structures: a primer

Canadian Journal of Civil Engineering ◽

10.1139/l09-104 ◽

2009 ◽

Vol 36 (11) ◽

pp. 1804-1815 ◽

Cited By ~ 26

Author(s):

Dan Palermo ◽

Ioan Nistor ◽

Younes Nouri ◽

Andrew Cornett

Keyword(s):

Structural Design ◽

Large Scale ◽

Solomon Islands ◽

Building Codes ◽

Experimental Program ◽

Test Results ◽

Significant Interest ◽

Design Documents ◽

Force Components ◽

Site Planning

The effects and estimation of tsunami-induced loading on near-shoreline structures located within inundation zones have recently gained significant interest from researchers, engineers, and government agencies. Building codes, namely the 2005 National building code of Canada, do not explicitly consider tsunami loading, as it is understood that inland structures can be protected by proper site planning. However, recent catastrophic events (Indian Ocean, 2004; Solomon Islands, 2007) indicate that tsunami loading should be considered in structural design. Presented herein is a review of force components that arise from tsunami-induced hydraulic bores running inland, along with proposed loading combinations and load cases readily applicable for building codes. Test results from a comprehensive experimental program conducted in a large-scale flume are also provided. A comparison of experimental results with force components provided in readily available design documents is presented, and suggestions for improvements are further discussed.

Download Full-text

Redox Chemistry of Actinide Ions in Wells−Dawson Heteropolyoxoanion Complexes

European Journal of Inorganic Chemistry ◽

10.1002/ejic.200300225 ◽

2003 ◽

Vol 2003 (16) ◽

pp. 2929-2936 ◽

Cited By ~ 18

Author(s):

Ming-Hsi Chiang ◽

L. Soderholm ◽

Mark R. Antonio

Keyword(s):

Redox Chemistry ◽

Actinide Ions

Download Full-text