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Selected AbstractsStripping Voltammetry at Microdisk Electrode Arrays: TheoryELECTROANALYSIS, Issue 24 2009Abstract Anodic stripping voltammetry (ASV) is an extremely powerful tool for detection of metal ions in solution through a two step process of preconcentration of the metal at the electrode surface, followed by electrodissolution. The second phase produces an electroanalytical response proportional to the amount of material deposited in the first phase. This paper utilizes theory to explore the electrochemical signals produced when considering ASV at a microelectrode or ultramicroelectrode arrays. The theory outlined is applicable mostly to thin mercury film absorption and metal adsorption. [source] Synthesis and Characterization of Alumina Microtubes in a Template Process from Short Carbon Fibers,ADVANCED ENGINEERING MATERIALS, Issue 5 2007Z. Pajkic A novel, two step process for synthesis of Al2O3 microtubes from short carbon fibers as templates is reported. In the first process step, the carbon fibers are coated with a Al-AlN-Al4C3 composite in a microwave plasma fluidized bed CVD process. The coated material is then being treated in a furnace on high temperature in air, resulting finaly with alumina microtubes (hollow fibers). [source] Graphoepitaxial Assembly of Symmetric Block Copolymers on Weakly Preferential SubstratesADVANCED MATERIALS, Issue 38 2010Eungnak Han Weakly preferential substrates were utilized in a single step process to direct the assembly of symmetric PS- b -PMMA. The thickness dependence of domain orientation on weakly preferential substrates was exploited to dictate the lateral ordering of perpendicular lamellae. [source] Synthesis and characterization of tritium labeled 2,3,4,9-tetrahydro-1H -carbazoles as potent DP receptor antagonistsJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 2 2004Carl Berthelette Abstract Tritium labeled 2,3,4,9-tetrahydro-1H -carbazole 1a and 2a were prepared in good yields with a specific activity of 7.0 Ci/mmol (214 GBq/mmol) and 4.2 Ci/mmol (155 GBq/mmol), respectively. Both compounds have been synthesized in high radiochemical purity by catalytic tritium,bromine exchange of the corresponding aryl bromide precursors. The 6-bromocarbazole precursors 7 and 8 were prepared as a mixture by a three step process, involving regioselective bromination of 3c with pyridinium tribromide, oxidation of thioether 4c using m -CPBA and hydrolysis of acylsultamcarbazole 5c. Finally, HPLC separation of the enantiomers afforded the 6-bromo precursors 7 and 8 in high diastereomeric ratio (dr 99% and dr 93% respectively). Copyright © 2004 John Wiley & Sons, Ltd. [source] Sulfoalkyl ether-alkyl ether cyclodextrin derivatives, their synthesis, NMR characterization, and binding of 6,-methylprednisoloneJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 11 2005Serena Tongiani Abstract The objective of this study is to see if random alkyl ethers of various sulfoalkyl ether cyclodextrins can be synthesized and characterized. The purpose of the alkylation was to test the hypothesis that an increase in the "height" of a cyclodextrins cavity would help in the binding/complexation of larger more structurally complex molecules. The synthesis of new cyclodextrin derivatives comprising a mixture of sulfoalkyl ether and alkyl ether substituents on the same cyclodextrin ring was performed in aqueous alkaline solutions using various sultones and alkylsulfates. The method presented provided an easy and efficient way to modify cyclodextrins avoiding the use of organic solvents and high quantities of alkylating agents and could be carried out in either a two step or "one pot" single step process. Purification was by neutralization followed by ultrafiltration. The derivatives were characterized by 1D, (1H and 13C), and a 2D NMR technique (HMQC, Heteronuclear Multiple Quantum Coherence). The combination of these techniques allowed an analysis of the degree of substitution and the site of substitution on the cyclodextrin (CD) nucleus. For both ,- and ,-CD, sulfoakylation was preferred on the 2,>,3,>,6 hydroxyls while alkylation was preferred 6,>,2,>,3. Due to the simultaneous presence of short alkyl ether chains and negatively charged sulfoalkyl ether chains, these mixed water-soluble cyclodextrin derivatives, especially those of ,-cyclodextrin, should be able to bind more complex drugs. The improved binding capacity of these new modified CDs with the model drug 6,-methylprednisolone is reported. © 2005 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 94:2380-2392, 2005 [source] The five steps toward Awakened LeadershipPERFORMANCE IMPROVEMENT, Issue 7 2008Joan F. Marques What is Awakened Leadership (AL)? This article reviews AWAKE, a five step process that can lead to the successful practice of AL as a tool toward human performance improvement. AL is a highly flexible meta-leadership style that integrates all distinctive leadership approaches into one all-encompassing way of living and leading. [source] Towards advanced circuit board materials: adhesion of copper foil to ultra-high molecular weight polyethylene compositePOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 6 2002Dmitry Abstract Polyethylene based composites are attractive materials for advanced circuit board applications because of their unique combination of properties: low dielectric constant and loss factor, light weight, high flexural modulus and low thermal expansion coefficient controlled in all spatial directions. This investigation describes a process to consolidate chopped fibers of ultra-high molecular weight polyethylene concurrently with its bonding to a copper foil. Bonding is affected by a thin sheet of low-density polyethylene, incorporating a crosslinking agent with a concentration gradient across the sheets thickness. In this single step process, the composite material is formed and bonded to the metal foil, achieving good adhesion without the use of extraneous glue. Copyright © 2002 John Wiley & Sons, Ltd. [source] | |||||||||||||