5,312 research outputs found

    On Collective Properties of Dense QCD Matter

    Get PDF
    A short review of the two recently analyzed collective effects in dense non-Abelian matter, the photon and dilepton production in nonequilibrium glasma and polarization properties of turbulent Abelian and non-Abelian plasmas, is given.Comment: 3 figure

    Ultrafast response of surface electromagnetic waves in an aluminum film perforated with subwavelength hole arrays

    Full text link
    The ultrafast dynamics of surface electromagnetic waves photogenerated on aluminum film perforated with subwavelength holes array was studied in the visible spectral range by the technique of transient photomodulation with 100 fs time resolution. We observed a pronounced blueshift of the resonant transmission band that reveals the important role of plasma attenuation in the optical response of nanohole arrays. The blueshift is inconsistent with plasmonic mechanism of extraordinary transmission and points to the crucial role of interference in the formation of transmission bands. The transient photomodulation spectra were successfully modeled within the Boltzmann equation approach for the electron-phonon relaxation dynamics, involving non-equilibrium hot electrons and quasi-equilibrium phonons.Comment: 4 pages, 3 figure

    Coherent acoustic vibration of metal nanoshells

    Full text link
    Using time-resolved pump-probe spectroscopy we have performed the first investigation of the vibrational modes of gold nanoshells. The fundamental isotropic mode launched by a femtosecond pump pulse manifests itself in a pronounced time-domain modulation of the differential transmission probed at the frequency of nanoshell surface plasmon resonance. The modulation amplitude is significantly stronger and the period is longer than in a gold nanoparticle of the same overall size, in agreement with theoretical calculations. This distinct acoustical signature of nanoshells provides a new and efficient method for identifying these versatile nanostructures and for studying their mechanical and structural properties.Comment: 5 pages, 3 figure

    GEO-ECOLOGICAL STUDY OF CENTRAL PIPELINE CORRIDORS IN GEORGIA

    Get PDF
    At present, the main pipelines represent the most profitable economic means in terms of transportation, supply and exploitation of energy resources. Since their laying is associated with a change in the natural environment, the ecological study of these corridors is a prerequisite. Geo-ecological study of the main pipelines is divided into three stages. This is the study of the pipeline route, to establish the existing background before the work begins. The second stage is the establishment of environmental impact during the laying of the pipeline. The third step is to monitor the environmental problems encountered during exploitation.The presented article gives a geo-ecological study of the corridors of gas pipelines in the section 1200, 1000 and 700 mm on the Kazbegi-Red Bridge (North-South) section. Carried out works represents the first stage of the study, and we have identified the physical and biological characteristics of the pipeline corridors. It was determined the purity of air, noise, chemical composition of soil, water and vegetation cover, as well as engineering and geological conditions of gas pipeline corridors. The results obtained do not exceed the values of the maximum permissible concentrations adopted in Georgia and in European countries, although Pl, Co, Ni and Cd show increased values directly near the gas pipeline.At present, the main pipelines represent the most profitable economic means in terms of transportation, supply and exploitation of energy resources. Since their laying is associated with a change in the natural environment, the ecological study of these corridors is a prerequisite. Geo-ecological study of the main pipelines is divided into three stages. This is the study of the pipeline route, to establish the existing background before the work begins. The second stage is the establishment of environmental impact during the laying of the pipeline. The third step is to monitor the environmental problems encountered during exploitation.The presented article gives a geo-ecological study of the corridors of gas pipelines in the section 1200, 1000 and 700 mm on the Kazbegi-Red Bridge (North-South) section. Carried out works represents the first stage of the study, and we have identified the physical and biological characteristics of the pipeline corridors. It was determined the purity of air, noise, chemical composition of soil, water and vegetation cover, as well as engineering and geological conditions of gas pipeline corridors. The results obtained do not exceed the values of the maximum permissible concentrations adopted in Georgia and in European countries, although Pl, Co, Ni and Cd show increased values directly near the gas pipeline

    Surface plasmon lifetime in metal nanoshells

    Full text link
    The lifetime of localized surface plasmon plays an important role in many aspects of plasmonics and its applications. In small metal nanostructures, the dominant mechanism restricting plasmon lifetime is size-dependent Landau damping. We performed quantum-mechanical calculations of Landau damping for the bright surface plasmon mode in a metal nanoshell. In contrast to the conventional model based on the electron surface scattering, we found that the damping rate decreases as the nanoshell thickness is reduced. The origin of this behavior is traced to the spatial distribution of plasmon local field inside the metal shell. We also found that, due to interference of electron scattering amplitudes from nanoshell's two metal surfaces, the damping rate exhibits pronounced quantum beats with changing shell thickness.Comment: 9 pages, 4 Figure

    Essential L-Amino Acid-Functionalized Graphene Oxide for Liquid Crystalline Phase Formation

    Full text link
    The colloidal 2D materials based on graphene and its modifications are of great interest when it comes to forming LC phases. These LC phases allow controlling the orientational order of colloidal particles, paving the way for the efficient processing of modified graphene with anisotropic properties. Here, we present the peculiarities of AA functionalization of GO, along with the formation of its LC phase and orientational behavior in an external magnetic field. We discuss the influence of pH on the GOLC, ultimately showing its pH-dependent behavior for GO-AA complexes. In addition, we observe different GO morphology changes due to the presence of AA functional groups, namely L-cysteine dimerization on the GO platform. The pH dependency of AA-functionalized LC phase of GO is examined for the first time. We believe that our studies will open new possibilities for applications in bionanotechnologies due to self-assembling properties of LCs and magnificent properties of GO.Comment: 10 pages, 16 figure
    corecore