1,946 research outputs found

    Adatom incorporation and step crossing at the edges of 2D nanoislands

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    Adatom incorporation into the ``faceted'' steps bordering the 2D nanoislands is analyzed. The step permeability and incorporation coefficients are derived for some typical growth situations. It is shown that the step consisting of equivalent straight segments can be permeable even in the case of fast egde migration if there exist factors delaying creation of new kinks. The step consisting of alternating rough and straight segments may be permeable if there is no adatom transport between neighboring segments through the corner diffusion.Comment: 3 pages, one figur

    Elliptic flow contribution to two-particle correlations at different orientations to the reaction plane

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    Collective anisotropic particle flow, a general phenomenon present in relativistic heavy-ion collisions, can be separated from direct particle-particle correlations of different physics origin by virtue of its specific azimuthal pattern. We provide expressions for flow-induced two-particle azimuthal correlations, if one of the particles is detected under fixed directions with respect to the reaction plane. We consider an ideal case when the reaction plane angle is exactly known, as well as present the general expressions in case of finite event-plane resolution. We foresee applications for the study of generic two-particle correlations at large transverse momentum originating from jet fragmentation.Comment: 5 pages, 3 figures, to be published as Rapid Communications in Phys.Rev.C Re-submit paper to with small improvements in text for better understanding, some minor changes in notation, and correcting one formula where a summation was forgotten. One new reference, one reference to conference report removed since full paper was already reference

    Fabrication and properties of L-arginine-doped PCL electrospun composite scaffolds

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    The article describes fabrication and properties of composite fibrous scaffolds obtained by electrospinning of the solution of poly({\epsilon}-caprolactone) and arginine in common solvent. The influence of arginine content on structure, mechanical, surface and biological properties of the scaffolds was investigated. It was found that with an increase of arginine concentration diameter of the scaffold fibers was reduced, which was accompanied by an increase of scaffold strength and Young modulus. It was demonstrated that porosity and water contact angle of the scaffold are independent from arginine content. The best cell adhesion and viability was shown on scaffolds with arginine concentration from 0.5 to 1 % wt

    Gravity Effect on Electrical Field Generation and Charge Carriers Transfer During Combustion Synthesis of Sulfides

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    The effect of gravity on the electric potential generated by the combustion synthesis of zinc sulfide is analyzed using the numerical simulation. Recent experimental studies on generation of electric voltage during combustion synthesis of zinc sulfide (ZnS) have revealed high voltage signals (4 V) with duration about 1 s, which are much higher than those produced by the gas–solid and solid–solid combustion reactions studied previously. These data have raised the question about mechanism of such a phenomenon. In our previous work we developed a novel (distributed) model describing the electric potential generation during combustion synthesis of sulfides (CSS) that didn\u27t count the effect of gravity. In this paper the simulations of heat - mass transfer, charge carriers motion, and voltage profiles taking into account the Earth gravity effect. The simulations confirms that the gravitation force strongly affects the emission of negatively charged sulfur ions as well as electrons and has a significant impact on the amplitude and temporal evolution of the combustion induced voltage. The voltage reduction up to four times has been observed numerically in the case when gravity acts in the direction coincident to that of the propagating combustion wave. Vice versa, the significant acceleration of the combustion and the voltage amplification due to the advection is simulated when gravity acts in the direction opposite to that of the propagating combustion wave

    Direct Photons at RHIC

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    The PHENIX experiment has measured direct photons in sNN=200\sqrt{s_{NN}} = 200 GeV Au+Au collisions and p+p collisions. The fraction of photons due to direct production in Au+Au collisions is shown as a function of pTp_T and centrality. This measurement is compared with expectation from pQCD calculations. Other possible sources of direct photons are discussed.Comment: 7 pages, 5 figures, presented at Hot Quarks 2004, Taos, N

    Transverse Pressure and Strangeness Dynamics in Relativistic Heavy Ion Reactions

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    Transverse hadron spectra from proton-proton, proton-nucleus and nucleus-nucleus collisions from 2 AGeV to 21.3 ATeV are investigated within two independent transport approaches (HSD and UrQMD). For central Au+Au (Pb+Pb) collisions at energies above Elab∼E_{\rm lab}\sim 5 AGeV, the measured K±K^{\pm} transverse mass spectra have a larger inverse slope parameter than expected from the default calculations. The additional pressure - as suggested by lattice QCD calculations at finite quark chemical potential μq\mu_q and temperature TT - might be generated by strong interactions in the early pre-hadronic/partonic phase of central Au+Au (Pb+Pb) collisions. This is supported by a non-monotonic energy dependence of v2/v_2/ in the present transport model.Comment: Proceedings of Strange Quark Matter 200

    Temperature independent diffuse scattering and elastic lattice deformations in relaxor PbMg1/3Nb2/3O3

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    The results of diffuse neutron scattering experiment on PbMg1/3Nb2/3O3 single crystal above the Burns temperature are reported. It is shown that the high temperature elastic diffuse component is highly anisotropic in low-symmetry Brillouin zones and this anisotropy can be described using Huang scattering formalism assuming that the scattering originates from mesoscopic lattice deformations due to elastic defects. The qualitative agreement between this model and the experimental data is achieved with simple isotropic defects. It is demonstrated that weak satellite maxima near the Bragg reflections can be interpreted as the finite resolution effect.Comment: 7 pages, 7 figure
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