55 research outputs found
The Amplitude of Non-Equilibrium Quantum Interference in Metallic Mesoscopic Systems
We study the influence of a DC bias voltage V on quantum interference
corrections to the measured differential conductance in metallic mesoscopic
wires and rings. The amplitude of both universal conductance fluctuations (UCF)
and Aharonov-Bohm effect (ABE) is enhanced several times for voltages larger
than the Thouless energy. The enhancement persists even in the presence of
inelastic electron-electron scattering up to V ~ 1 mV. For larger voltages
electron-phonon collisions lead to the amplitude decaying as a power law for
the UCF and exponentially for the ABE. We obtain good agreement of the
experimental data with a model which takes into account the decrease of the
electron phase-coherence length due to electron-electron and electron-phonon
scattering.Comment: New title, refined analysis. 7 pages, 3 figures, to be published in
Europhysics Letter
Effect of Celergen, a marine derivative, on in vitro hepatocarcinogenesis
The aim of this study was to test for a potential anticarcinogenic effect of Celergen, a marine derivative devoid of traceable amounts of inorganic arsenic, on cell proliferation, cell cycle progression and apoptosis in the HepG2 human liver cancer cell
line. Celergen significantly inhibited the proliferation of cancer cells in a dose-dependent manner while limiting the cell cycle progression at the G1 phase and
significantly inducing apoptosis. Further examination showed that Celergen enhanced expression of the p21CIPl1WAF1, GADD153 genes and downregulated the
c-myc gene. These results suggest that Celergen exerts promising chemopreventive properties to be further investigated
Shear and Rotatory Inertia Effects on the Large Amplitude Vibration of the Initially Imperfect Plates
TRANSIENT WAVE-PROPAGATION IN LAYERED MEDIA CONDUCTING HEAT
Transient wave propagation in thermoelastic layered composites consisting of alternating isotropic, homogeneous and linearly elastic high-strength reinforcing and low-strength matrix layers is investigated. The layers of the composite medium can be plane, cylindrical or spherical. The inner surfaces of the composite bodies are subjected to uniform time dependent dynamic inputs. A common formulation is employed for the three types of layered media. The generalized theory of thermoelasticity is used, with thermal relaxation predicting finite wave speeds for thermal disturbances. The method of characteristics is employed to obtain the solutions. Curves are plotted denoting the variations of normal stresses with time at different locations and variations of stresses along the thicknesses of the bodies at different times. The curves reveal the thermal and geometric dispersions in the wave profiles and the effects of reflections and refractions at the boundaries and the interfaces of the layers
Response of a completely free beam on a tensionless Pasternak foundation subjected to dynamic load
Earthquake performance of the two approach viaducts of the bosphorus suspension bridge
The main purpose of this paper is to determine the dynamic characteristics and the structural stability of the two approach viaducts of the Bosphorus Suspension Bridge under the expected stresses that would be caused during earthquake conditions. The Ortakoy and the Beylerbeyi approach viaducts constitute the side spans of the bridge at two locations. The bridge's main span over the Bosphorus is suspended, whereas they are supported at the base at either end. For the numerical investigation of the viaducts, 3-D computational structural finite element-FE models were developed. Their natural frequencies and the corresponding mode shapes were obtained, analyzed, presented and compared. The performances of the viaducts, under earthquake conditions, were studied considering the P-Delta effects implementing the push-over (POA) and the non-linear time-history analyses (NTHA). For the NTHA, three earthquake ground motions were generated depending on the location of the bridge. Seismic performances of the viaducts were determined in accordance with the requirements of the tur Seismic Code for the Earthquake Design of Railways Bridges (TSC-R/2008) and those of Caltrans (CALTRANS-2001) given for Seismic Design of Steel Bridges, separately. Furthermore, the investigation was extended for evaluating the possible need for retrofitting in the future. After the analysis of the resultant data, a retrofit recommendation for the viaducts was presented. © 2016 Techno-Press, Ltd
Pollen morphology of the genus Lamium L. (Lamiaceae) and its systematic implications
This is the first comprehensive palynological investigation of the genus Lamium. The pollen morphology of 48 taxa (including species, subspecies and varieties) of the genus Lamium was investigated and documented using light microscopy (LM) and scanning electron microscopy (SEM). Lamium pollen is small to medium sized (I) = 21.65-39.96 mu m), oblate-spheroidal to subprolate in shape and tricolpate. Three major exine sculpturing patterns (reticulate, granulate and microreticulate) were observed. The results indicated that the exine sculpturing pattern of Lamium is systematically informative at sectional level, but not at the species and infraspecific levels. In the present study, the palynological data are compared with available phylogenetic studies to evaluate the systematic value of pollen characters in the genus. Analysis show that; (1) Mennema's infrageneric classification is partly corroborated by our palynological data, (2) recent phylogenetic analysis on the genus and our results are partly corroborated, and (3) pollen morphology supports the inclusion of L. galeobdolon (=Galeobdolon), L. orientale and L. multifidum (=Wiedemannia) in Lamium. (4) Variation in exine sculpturing pattern have systematic importance particularly at sectional level. (C) 2016 Elsevier GmbH. All rights reserved
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