Search results for "Nucleation"

From Single Molecules to Nanostructured Functional Materials: Formation of a Magnetic Foam Catalyzed by Pd@FexO Heterodimers

2017

Multicomponent nanostructures containing purely organic or inorganic as well as hybrid organic–inorganic components connected through a solid interface are, unlike conventional spherical particles, able to combine different or even incompatible properties within a single entity. They are multifunctional and resemble molecular amphiphiles, like surfactants or block copolymers, which makes them attractive for the self-assembly of complex structures, drug delivery, bioimaging, or catalysis. We have synthesized Pd@FexO heterodimer nanoparticles (NPs) to fabricate a macroporous, hydrophobic, magnetically active, three-dimensional (3D), and template-free hybrid foam capable of repeatedly separati…

Initial stages of self-assembled InAs/InP(001) quantum wire formation

2007

4 páginas, 2 figuras.-- PACS codes: 78.67.Lt; 68.65.La; 68.37.Ps.-- Comunicación oral presentada a la 14ª International Conference on Molecular Beam Epitaxy - MBE XIV celebrada en Tokio (Japón) del 3 al 8 de Septiembre de 2006.

In situ nucleation of carbon nanotubes by the injection of carbon atoms into metal particles.

2007

The synthesis of carbon nanotubes (CNTs) of desired chiralities and diameters is one of the most important challenges in nanotube science and achieving such selectivity may require a detailed understanding of their growth mechanism. We report the formation of CNTs in an entirely condensed phase process that allows us, for the first time, to monitor the nucleation of a nanotube on the spherical surface of a metal particle. When multiwalled CNTs containing metal particle cores are irradiated with an electron beam, carbon from graphitic shells surrounding the metal particles is ingested into the body of the particle and subsequently emerges as single-walled nanotubes (SWNTs) or multiwalled nan…

Parenchyma-sparing surgery for renal tumors

1991

Between 1969 und 1989 conservative surgery for kidney tumors was performed in 123 patients. In 49 patients there was an imperative indication for a parenchyma-sparing operation because nephrectomy would have made dialysis obligatory. Thirty-five of these 49 patients show no signs of tumor progression after a mean follow-up of 4.5 years. Known metastases were present in 3 of 6 patients who died as a result of their tumors. In two patients there was a recurrence after 1 and 5 years, respectively, requiring a second organ-preserving operation. In one further patient we suspect that multiple small tumor lesions may be present 2 years after the first operation. In 74 patients with a healthy cont…

Microstructure development during NiAl intermetallic synthesis in reactive Ni–Al nanolayers: Numerical investigations vs. TEM observations

2013

Abstract Heterogeneous reactions leading to the formation of intermetallic compounds in nanometric Ni–Al multilayer system are examined both numerically and experimentally. On the numerical side, the reactivity of a layered Ni–Al–Ni system is studied by means of molecular dynamics simulations, using an embedded-atom method (EAM) potential. The mechanism of nucleation and growth of the intermetallic phase is determined. Four main stages in the reactive process, which lead to the formation of rounded shape grains of intermetallic phase at the Ni–Al interface, are delineated. On the experimental side, TEM imaging of quenched samples revealed the behavior of the Ni–Al reactive foils and showed …

Nucleation kinetics in deionized charged colloidal suspension

2011

A systematic experimental study on the nucleation, crystallization and crystal-growth of one-componentcharged colloidal particles (122 nm diluted in pure water with densities between 0.5 μm−3bnpb5 ...

Experimental visualization of inoculation using a charged colloidal model system

2012

Inoculation is widely used to tune the microstructure of a polycrystalline solid from the melt and thus its material properties. We present here a systematic time resolved experimental study of inoculation in a charged colloidal model system investigating the changes of the crystallization scenario upon adding spherical seeds and show that the nucleation kinetics solely determines the resulting microstructure.

Nucleation mechanisms and spatial hetereogeneity in insulin amyloid fibrils formation

2008

Nucleation mechanism of Lysozyme at physiological pH

2010

Bases for the synthesis of nanoparticulated silicas with bimodal hierarchical porosity

2006

Porous silicas with pore sizes at two length scales (meso and large meso/macroporous) have been prepared through a one-pot surfactant assisted procedure by using a simple template agent and starting from silicon atrane complexes as hydrolytic inorganic precursors. The special organization of these bimodal porous silicas can be related to the nanometric character of their constituent mesoporous particles. Whereas the small intra-particle mesopore system is generated by the templating effect of the surfactant, the large pore system is defined by inter-particle voids. We have studied the effect of different procedural parameters on the small pore system and also on the nucleation and growth of…