Changes in the structure of tethered chain molecules as predicted by density functional approach

We use a version of the density functional theory to study the changes in the height of the tethered layer of chains built of jointed spherical segments with the change of the length and surface density of chains. For the model in which the interactions between segments and solvent molecules are the same as between solvent molecules we have discovered two effects that have not been observed in previous studies. Under certain conditions and for low surface concentrations of the chains, the height of the pinned layer may attain a minimum. Moreover, for some systems we observe that when the temperature increases, the height of the layer of chains may decrease.Comment: 13 pages, 7 figure

The liquid-vapor interface of the restricted primitive model of ionic fluids from a density functional approach

We investigate the liquid-vapor interface of the restricted primitive model for an ionic fluid using a density functional approach. The applied theory includes the electrostatic contribution to the free energy functional arising from the bulk energy equation of state and the mean spherical approximation for a restricted primitive model, as well as the associative contribution, due to the formation of pairs of ions. We compare the density profiles and the values of the surface tension with previous theoretical approaches.Comment: 12 pages, 8 figure

Defects and Dopants in Silicon Nanowires Produced by Metal-Assisted Chemical Etching

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Adsorption of chain molecules in pores with crystalline walls: a density functional approach

A microscopic density functional theory of adsorption of chain molecules on the attractive solid surfaces of crystalline symmetry is developed. The proposed approach is based on the expansions of one-particle functions into two-dimensional Fourier series. Illustrative calculations for dimers, 8- and 16-mers adsorbed on a (100) fcc crystal surface indicate the effect of the periodicity of the adsorbing potential on the structure of the adsorbed layer and thermodynamics of adsorption.Розвинуто мiкроскопiчну теорiю функцiоналу густини для вивчення адсорбцiї ланцюгових молекул на притягальних твердих поверхнях кристалiчної симетрiї. Запропонований пiдхiд ґрунтується на розкладах одночастинкових функцiй у двовимiрнi ряди Фур’є. Для iлюстрацiї проведено обчислення для димерiв, 8- i 16-мерiв, що адсорбованi на кристалiчнiй поверхнi (100) fcc, якi демонструють вплив перiодичностi адсорбуючого потенцiалу на структуру адсорбованого шару i термодинамiку адсорбцiї

Spontaneous polarisation of the neutral interface for valence asymmetric coulombic systems

In this paper, we discuss the phenomenon of a spontaneous polarisation of a neutral hard planar interface for valence asymmetric coulombic systems. Within a field theoretical description, we account for the existence of non trivial charge density and electric potential profiles. The analysis of the phenomenon shows that the effect is related to combinatorics in relation with the existence of the two independent species cations and anions. This simple and basic feature is related to the quantum mechanical properties of the system. The theoretical results are compared with numerical simulations data and are shown to be in very good agreement, which a fortiori justifies our physical interpretation.Comment: 12 pages, 11 figure

Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal