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Cluster Growth (cluster + growth)

Distribution by Scientific Domains

Chemistry	50%

Selected Abstracts

Studies on the Formation of CdS Nanoparticles from Solutions of (NMe4)4[Cd10S4(SPh)16]

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 15 2010
Maria Bendova
Abstract The stepwise cluster growth, and formation of CdS nanoparticles from solutions of (NMe4)4[Cd10S4(SPh)16] in dimethyl sulfoxide (DMSO), dimethylformamide (DMF) and acetonitrile was investigated. Cluster growth is fast in DMSO and DMF at room temperature, and slow in acetonitrile at elevated temperatures. Larger sulfide clusters (initially Cd32, then Cd54) are initially formed, which upon further growth eventually give rise to CdS nanoparticles. Strong evidence was found that the byproduct formed during the reaction in DMSO is mononuclear [Cd(SPh)x(DMSO)y](2,x) (x , 3). [source]

Clusters, Power and Place: Inequality and Local Growth in Time,Space

GEOGRAFISKA ANNALER SERIES B: HUMAN GEOGRAPHY, Issue 2 2002
Harald Bathelt
The argument of this paper is that a deeper appreciation of the nature of the power relationships between firms and the circuits of power that bind them together is key to understanding how clusters function , including how they might emerge and how they might decline. We begin to develop a conceptualization that allows us to generate a deeper understanding of the processes that enable the production and reproduction of enterprise clusters under some combinations of circumstances but not others. The sections of the paper explore: (1) concepts of power and circuits of power including their spatialities; (2) the temporarily stabilized relationships which occur in clusters of economic activity; (3) the openness and permeability of clusters as a way of understanding conditions that foster cluster growth; (4) a tentative integration of concepts. From this reading of the concepts of clustering and power we draw the conclusion that clusters are, at any particular point in time, temporary and transient conjunctures of interfirm relationships. They depend on specific circumstances in ,time,space' and, because of their very transience and specificity, those conditions might be very difficult if not impossible to create through the blunt instruments of policy. [source]

Synthesis and Catalytic Applications of Self-Assembled Carbon Nanofoams,

ADVANCED MATERIALS, Issue 2 2008
J. García-Martínez
A new surfactant-templated carbon material, carbon nanofoam (CNF), has been synthesized with a semicrystalline and conductive framework, high surface area and interconnected porous structure, and prepared in a wide variety of bulk shapes and forms. CNF was also successfully applied as a support for palladium in the Heck coupling reaction. Pd/CNF catalyst exhibited negligible Pd cluster growth and agglomeration, and retained high activity even after multiple runs. [source]

First principles study of small palladium cluster growth and isomerization

INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 7 2007
Chen Luo
Abstract Structures and physical properties of small palladium clusters Pdn up to n = 15 and several selected larger clusters were studied using density functional theory under the generalized gradient approximation. It was found that small Pdn clusters begin to grow 3-dimensionally at n = 4 and evolve into symmetric geometric configurations, such as icosahedral and fcc -like, near n = 15. Several isomers with nearly degenerate average binding energies were found to coexist and the physical properties of these clusters were calculated. For several selected isomers, relatively moderate energy barriers for structural interchange for a given cluster size were found, implying that isomerization could readily occur under ambient conditions. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007 [source]