Migration from Turkey and the Uncertainty of the Accession of Turkey to the EU

There is a fear that, if Turkey were given admission to the EU, massive migration to the other member countries of the EU would result. This paper develops a theoretical framework for the migration decision that takes into consideration the impact on uncertainty of some of the important economic and social variables that are addressed by the EU membership and institutions. It emphasizes future expectations of living conditions and the level of uncertainty associated with them as a key variable in making migration decisions. It suggests that the more prosperous and stable Turkey is expected to be in the future, the less likely a person will now want to migrate. Hence, the greater certainty now that Turkey will gain admission in to EU, the more attractive is it for potential migrants to remain in Turkey. This framework suggests that measures to hinder Turkey's entry into the EU by having national referendums to approve its entry will increase the uncertainty of the future economic and social prospects in Turkey and will encourage migrants to migrate now to the member countries of the EU.Turkey, Migration, Uncertainty, Accession, European Union

Migration from Turkey and the uncertainty of the accession of Turkey to the EU

There is a fear that if Turkey were given admission to the EU massive migration to the other member countries of the EU would result. This paper develops a theoretical framework for the migration decision that takes into consideration the impact on uncertainty of some of the important economic and social variables that are addressed by the EU membership and institutions. It emphasizes future expectations of living conditions and the level of uncertainty associated with them as a key variable in making migration decisions. It suggests that the more prosperous and stable Turkey is expected to be in the future the less likely a person will now want to migrate. Hence, the greater certainty now that Turkey will gain admission in to EU, the more attractive is it for potential migrants to remain in Turkey. This framework suggests that measures to hinder Turkey's entry into the EU by having national referendums to approve its entry will increase the uncertainty of the future economic and social prospects in Turkey and will encourage migrants to migrate now to the member countries of the EU

Molecular random tilings as glasses

We have recently shown [Blunt et al., Science 322, 1077 (2008)] that p-terphenyl-3,5,3',5'-tetracarboxylic acid adsorbed on graphite self-assembles into a two-dimensional rhombus random tiling. This tiling is close to ideal, displaying long range correlations punctuated by sparse localised tiling defects. In this paper we explore the analogy between dynamic arrest in this type of random tilings and that of structural glasses. We show that the structural relaxation of these systems is via the propagation--reaction of tiling defects, giving rise to dynamic heterogeneity. We study the scaling properties of the dynamics, and discuss connections with kinetically constrained models of glasses.Comment: 5 pages, 5 figure

Fullerenes as adhesive layers for mechanical peeling of metallic, molecular and polymer thin films

We show that thin films of C60 with a thickness ranging from 10 to 100 nm can promote adhesion between a Au thin film deposited on mica and a solution-deposited layer of the elastomer polymethyldisolaxane (PDMS). This molecular adhesion facilitates the removal of the gold film from the mica support by peeling and provides a new approach to template stripping which avoids the use of conventional adhesive layers. The fullerene adhesion layers may also be used to remove organic monolayers and thin films as well as two-dimensional polymers which are pre-formed on the gold surface and have monolayer thickness. Following the removal from the mica support the monolayers may be isolated and transferred to a dielectric surface by etching of the gold thin film, mechanical transfer and removal of the fullerene layer by annealing/dissolution. The use of this molecular adhesive layer provides a new route to transfer polymeric films from metal substrates to other surfaces as we demonstrate for an assembly of covalently-coupled porphyrins

Theory, Simulation and Nanotechnological Applications of Adsorption on a Surface with Defects

Theory of adsorption on a surface with nanolocal defects is proposed. Two efficacy parameters of surface modification for nanotechnological purposes are introduced, where the modification is a creation of nanolocal artificial defects. The first parameter corresponds to applications where it is necessary to increase the concentration of certain particles on the modified surface. And the second one corresponds to the pattern transfer with the help of particle self-organization on the modified surface. The analytical expressions for both parameters are derived with the help of the thermodynamic and the kinetic approaches for two cases: jump diffusion and free motion of adsorbed particles over the surface. The possibility of selective adsorption of molecules is shown with the help of simulation of the adsorption of acetylene and benzene molecules in the pits on the graphite surface. The process of particle adsorption from the surface into the pit is theoretically studied by molecular dynamic technique. Some possible nanotechnological applications of adsorption on the surface with artificial defects are considered: fabrication of sensors for trace molecule detection, separation of isomers, and pattern transfer.Comment: 12 pages, 2 Postscript figures. Submitted to Surface Science (1998

Nucleation and early stages of layer-by-layer growth of metal organic frameworks on surfaces

High resolution atomic force microscopy (AFM) is used to resolve the evolution of crystallites of a metal organic framework (HKUST-1) grown on Au(111) using a liquid-phase layer-by-layer methodology. The nucleation and faceting of individual crystallites is followed by repeatedly imaging the same submicron region after each cycle of growth and we find that the growing surface is terminated by {111} facets leading to the formation of pyramidal nanostructures for [100] oriented crystallites, and triangular [111] islands with typical lateral dimensions of tens of nanometres. AFM images reveal that crystallites can grow by 5−10 layers in each cycle. The growth rate depends on crystallographic orientation and the morphology of the gold substrate, and we demonstrate that under these conditions the growth is nanocrystalline with a morphology determined by the minimum energy surface

Opening an energy gap in an electron double layer system at integer filling factor in a tilted magnetic field

We employ magnetocapacitance measurements to study the spectrum of a double layer system with gate-voltage-tuned electron density distributions in tilted magnetic fields. For the dissipative state in normal magnetic fields at filling factor $\nu=3$ and 4, a parallel magnetic field component is found to give rise to opening a gap at the Fermi level. We account for the effect in terms of parallel-field-caused orthogonality breaking of the Landau wave functions with different quantum numbers for two subbands.Comment: 4 pages, 4 figures included, to appear in JETP Letter

Organisation and ordering of 1D porphyrin polymers synthesised by on-surface Glaser coupling

One-dimensional polymer chains consisting of π-conjugated porphyrin units are formed via Glaser coupling on a Ag(111) surface. Scanning probe microscopy reveals the covalent structure of the products and their ordering. The conformational flexibility within the chains is investigated via a comparision of room temperature and cryogenic measurements

Weiss Oscillations in Surface Acoustic Wave Propagation

The interaction of a surface acoustic wave (SAW) with a a two-dimensional electron gas in a periodic electric potential and a classical magnetic field is considered. We calculate the attenuation of the SAW and its velocity change and show that these quantities exhibit Weiss oscillations.Comment: 4 pages REVTEX, 2 figures included as eps file

Magnetoresistance of a two-dimensional electron gas with spatially periodic lateral modulations: Exact consequences of Boltzmann's equation

On the basis of Boltzmann's equation, and including anisotropic scattering in the collision operator, we investigate the effect of one-dimensional superlattices on two-dimensional electron systems. In addition to superlattices defined by static electric and magnetic fields, we consider mobility superlattices describing a spatially modulated density of scattering centers. We prove that magnetic and electric superlattices in $x$-direction affect only the resistivity component $\rho_{xx}$ if the mobility is homogeneous, whereas a mobility lattice in $x$-direction in the absence of electric and magnetic modulations affects only $\rho_{yy}$. Solving Boltzmann's equation numerically, we calculate the positive magnetoresistance in weak magnetic fields and the Weiss oscillations in stronger fields within a unified approach.Comment: submitted to PR