40 research outputs found
Collider aspects of flavour physics at high Q
This review presents flavour related issues in the production and decays of
heavy states at LHC, both from the experimental side and from the theoretical
side. We review top quark physics and discuss flavour aspects of several
extensions of the Standard Model, such as supersymmetry, little Higgs model or
models with extra dimensions. This includes discovery aspects as well as
measurement of several properties of these heavy states. We also present public
available computational tools related to this topic.Comment: Report of Working Group 1 of the CERN Workshop ``Flavour in the era
of the LHC'', Geneva, Switzerland, November 2005 -- March 200
Sorption properties of modified single-walled carbon nanotubes
Single walled carbon nanotubes (SWNTs), with high carboxylic acid content, were chemically modified in order to develop hydrophilic and organophilic analogues. The hydrophilic SWNTs were prepared by wrapping a water-soluble polymer, namely poly (sodium 4-styrene sulfonate) (PSSNa) around the pristine SWNTs, while the organophilic SWNTs were developed by forming amide bonds with oleylamine (C18H37N). The modification of carbon nanotubes was studied through IR spectroscopy. Moreover, the sorption properties of pristine and modified carbon nanotubes were studied by using adsorbates, which differ in polarity (i.e. water, ethanol and n-hexane). Based on these measurements it is concluded that the sorption behaviour of the SWNTs has been completely modified after the treatment, since the hydrophilic and organophilic carbon nanotubes reveal enhanced selectivity of water and n-hexane respectively. © 2006 Elsevier Inc. All rights reserved
Synthesis and characterisation of carbon nanotube modified anodised alumina membranes
Carbon nanotubes (CNTs) are considered as ideal model sorbent systems for studying the effect of pore size and surface characteristics on the sorption and transport properties of porous solids. In this study we synthesized CNTs on anodised alumina disks with pore sizes of 20, 100 and 200 nm. The disks were initially immersed into a nickel nitrate solution and purged with hydrogen at elevated temperatures in order to form metallic nickel nanoparticles. CNTs were thereinafter grown by CVD at 973 K using a mixture of acetylene and argon. When a nickel catalyst was involved, the CVD period adequate for CNT's growth was 15 min for all the templates. In absence of the catalyst the sufficient CVD duration was about 6 h for the 20 nm templates, while no CNT formation has been observed for the 100 and 200 nm templates during this period. Adsorption of n-hexane and relative permeability (RP) of the n-hexane/nitrogen system were applied to examine the resulting carbon nanotube membranes. Since the permeation of the non-condensable gas is governed by the Knudsen diffusion mechanism, a pore size distribution (PSD) was extracted directly from the derivative of the permeance curve against pore radii, after relating the latter with the equilibrium vapour pressure via the Kelvin equation and an accurate t-curve. These experiments were useful for the determination of the pore size distribution of the remaining open gaps of the developed membranes and gave an insight on the factors affecting the CNTs growth. © 2007 Elsevier Inc. All rights reserved
Few layer graphenes decorated with silver nanoparticles
Graphite oxide (GO) powder was irradiated in a microwave oven and lightweight expanded graphite oxide (EGO) powder with high BET surface area 1316 m2/g was obtained. Activation of EGO was performed by impregnation in KOH solution and high temperature treatment under Ar flow, followed by annealing in vacuum (t-EGO). KOH acted more as a reducing agent diminishing the defects than as a surface modifier for high porosity. EGO and t-EGO were further decorated with Ag nanoparticles (∼40 nm) applying solar light irradiation. Along with Ag deposition the structural defects of the graphene were reduced upon photo-irradiation. It was established that among the bare graphenes the EGO exhibited the highest capacitance. From the Ag-containing composites, the KOH activated EGO acted as a supercapacitor, while the non-activated EGO as a resistant
Few layer graphenes decorated with silver nanoparticles
Graphite oxide (GO) powder was irradiated in a microwave oven and lightweight expanded graphite oxide (EGO) powder with high BET surface area 1316 m2/g was obtained. Activation of EGO was performed by impregnation in KOH solution and high temperature treatment under Ar flow, followed by annealing in vacuum (t-EGO). KOH acted more as a reducing agent diminishing the defects than as a surface modifier for high porosity. EGO and t-EGO were further decorated with Ag nanoparticles (∼40 nm) applying solar light irradiation. Along with Ag deposition the structural defects of the graphene were reduced upon photo-irradiation. It was established that among the bare graphenes the EGO exhibited the highest capacitance. From the Ag-containing composites, the KOH activated EGO acted as a supercapacitor, while the non-activated EGO as a resistant