Search results for "GOLD"
showing 10 items of 1320 documents
Words with the Maximum Number of Abelian Squares
2015
An abelian square is the concatenation of two words that are anagrams of one another. A word of length n can contain \(\varTheta (n^2)\) distinct factors that are abelian squares. We study infinite words such that the number of abelian square factors of length n grows quadratically with n.
Quality control of gold nanoparticles as pharmaceutical ingredients
2019
Abstract Nanoparticles are being developed for a wide range of medical applications such as, controlled release, drug delivery systems or imagery, theranostics, implants…. For the moment, there is no legal definition of nanoparticles or nanomaterials for therapeutic use. The specific case of gold nanoparticles is not an exception: their current definition as nanoparticle material does not correspond to classic pharmaceutical ingredients as described in Pharmacopoeias. In this study, more than 30 different batches of citrate stabilized gold nanoparticles (AuNP) were synthesized and analyzed thanks to both classical approaches (UV–Vis spectrophotometry, dynamic light scattering coupled or not…
Prediction of new inorganic molecules with quantum chemical methods
2006
Quantum chemistry can today be employed to invent new molecules and explore unknown molecular bonding. An overview of novel species containing metals bound to polynitrogen clusters is presented. The prediction of metal polyhydrides is discussed. Finally, some species containing gold that behaves as a halogen are described, together with recent advances in actinide chemistry and exploration of the nature of the actinide–actinide chemical bonding.
Strong CP-violation in an effective chiral lagrangian approach
1991
21 páginas, 2 figuras.-- CERN-TH-6071-91
Resonance saturation of the chiral couplings at next-to-leading order in 1/N-C
2009
9 páginas, 3 figuras.-- ISI article identifier:000266408300099.-- ArXiv pre-print avaible at:http://arxiv.org/abs/0903.2440
The A5 and the pion field
2005
In this talk, an SU(Nf)xSU(Nf)Yang-Mills model with a compact extra-dimension is used to describe the spin-1 mesons and pions of massless QCD in the large-Nc. The right 4D symmetry and symmetry-breaking pattern is produced by imposing appropriate boundary conditions. The Goldstone boson fields are constructed using a Wilson line. We derive the low-energy limit (chiral lagrangian), discuss rho-meson dominance, sum rules between resonance couplings and the relation with the QCD high-energy behavior. Finally, we provide an analytic expression for the two-point function of vector and axial currents.
Proton Spin in Chiral Quark Models
1997
The spin and flavor fractions of constituent quarks in the proton are obtained from their chiral fluctuations involving Goldstone bosons. SU(3) flavor symmetry breaking suggested by the mass difference between the strange and up, down quarks is included, and this improves the agreement with the data markedly.
Finite Volume Scaling of Pseudo Nambu-Goldstone Bosons in QCD
2008
We consider chiral perturbation theory in a finite volume and in a mixed regime of quark masses. We take N_l light quarks near the chiral limit, in the so-called epsilon-regime, while the remaining N_h quarks are heavier and in the standard p-regime. We compute in this new mixed regime the finite-size scaling of the light meson correlators in the scalar, pseudoscalar, vector and axial vector channels.Using the replica method, we easily extend our results to the partially quenched theory. With the help of our results, lattice QCD simulations with 2+1 flavors can safely investigate pion physics with very light up and down quark masses even in the region where the pion's correlation length ove…
Mapping geographical inequalities in oral rehydration therapy coverage in low-income and middle-income countries, 2000-17
2020
Background: Oral rehydration solution (ORS) is a form of oral rehydration therapy (ORT) for diarrhoea that has the potential to drastically reduce child mortality; yet, according to UNICEF estimates, less than half of children younger than 5 years with diarrhoea in low-income and middle-income countries (LMICs) received ORS in 2016. A variety of recommended home fluids (RHF) exist as alternative forms of ORT; however, it is unclear whether RHF prevent child mortality. Previous studies have shown considerable variation between countries in ORS and RHF use, but subnational variation is unknown. This study aims to produce high-resolution geospatial estimates of relative and absolute coverage o…
Spectral Measurement of Photon Emission from Individual Gold Nanoparticles Using Scanning Tunneling Microscopy
2016
The light emission spectra of individual Au nanoparticles induced by a scanning tunneling microscope (STM) have been investigated. Two-dimensional ensembles of tunnel-coupled Au particles were prepared by thermal evaporation onto a native oxide silicon wafer in ultrahigh vacuum (10 – 9 mbar). Our STM measurements show a single peak at photon energy 1.6 eV in the tunneling mode and two peaks at 2.2 eV (connected with the Mie plasmon) and 1.45 eV (a new peak which was not discussed in literature before) in the field emission mode.