13,390 research outputs found
A DISAGGREGATED TIME-SERIES ANALYSIS OF EXPORT-BASE MODELS: A CASE STUDY ON ELKO COUNTY OF NEVADA
An important issue of debate in economic base literature is whether the export-base theory applies best to the short run, the long run, or both. An attempt is being made here in answering this crucial question by applying a two-step test for cointegration on quarterly employment data, and in gaining insights as to whether or not any unequivocal judgment can be made regarding the validity of the economic base hypothesis.International Relations/Trade,
Optical Properties for Thin Film of Coumarin 334 Organic Laser Dye doped with PVA Polymer and Al2O3 Nanoparticles
Background:
In this work, the optical properties for thin film of Coumarin 334 organic laser dye doped with PVA polymer and AL2O3 nanoparticles are determined at different concentrations, dissolved in ethanol solvent.
Methods:
Solutions at concentration (10-4 M) from coumarin (334) dye in ethanol solvent at Different concentrations from dye (1, 3, 5, and 7) ×10-5 M were prepared.
Results:
The AFM measurements show that the grain size, root mean square and roughness belong to the surface of the thin films rises with thickness rise for thin films . It has also increased the absorbance due to the increase in concentration.
Conclusion:
By using Gaussian beam from CW pulsed laser at 457 nm, we used Z-scan to study the nonlinear optical properties. The nonlinearity of thin film highly excels the pure dye solutions
Damage in graphene due to electronic excitation induced by highly charged ions
Graphene is expected to be rather insensitive to ionizing particle radiation.
We demonstrate that single layers of exfoliated graphene sustain significant
damage from irradiation with slow highly charged ions. We have investigated the
ion induced changes of graphene after irradiation with highly charged ions of
different charge states (q = 28-42) and kinetic energies E_kin = 150-450 keV.
Atomic force microscopy images reveal that the ion induced defects are not
topographic in nature but are related to a significant change in friction. To
create these defects, a minimum charge state is needed. In addition to this
threshold behaviour, the required minimum charge state as well as the defect
diameter show a strong dependency on the kinetic energy of the projectiles.
From the linear dependency of the defect diameter on the projectile velocity we
infer that electronic excitations triggered by the incoming ion in the
above-surface phase play a dominant role for this unexpected defect creation in
graphene
Fast and robust spin manipulation in a quantum dot by electric fields
We apply an invariant-based inverse engineering method to control by
time-dependent electric fields electron spin dynamics in a quantum dot with
spin-orbit coupling in a weak magnetic field. The designed electric fields
provide a shortcut to adiabatic processes that flips the spin rapidly, thus
avoiding decoherence effects. This approach, being robust with respect to the
device-dependent noise, can open new possibilities for the spin-based quantum
information processing.Comment: 7 pages, 6 figures, with supplemental material. Errors in the
published version have been correcte
Single crystal growth, structure and magnetic properties of Pr2Hf2O7 pyrochlore
Large single crystals of the pyrochlore Pr2Hf2O7 have been successfully grown
by the floating zone technique using an optical furnace equipped with high
power Xenon arc lamps. Structural investigations have been carried out by both
synchrotron X-ray and neutron powder diffraction to establish the
crystallographic structure of the materials produced. The magnetic properties
of the single crystals have been determined for magnetic fields applied along
different crystallographic axes. The results reveal that Pr2Hf2O7 is an
interesting material for further investigations as a frustrated magnet. The
high quality of the crystals produced make them ideal for detailed
investigations, especially those using neutron scattering techniques.Comment: Accepted for publication in J. Phys.: Condens. Matte
Fibrosis in diabetes complications: Pathogenic mechanisms and circulating and urinary markers
Diabetes mellitus is characterized by a lack of insulin causing elevated blood glucose, often with associated insulin resistance. Over time, especially in genetically susceptible individuals, such chronic hyperglycemia can cause tissue injury. One pathological response to tissue injury is the development of fibrosis, which involves predominant extracellular matrix (ECM) accumulation. The main factors that regulate ECM in diabetes are thought to be pro-sclerotic cytokines and protease/anti-protease systems. This review will examine the key markers and regulators of tissue fibrosis in diabetes and whether their levels in biological fluids may have clinical utility
Correlation Functions and Spin
The k-electron correlation function of a free chaotic electron beam is
derived with the spin degree of freedom taken into account. It is shown that it
can be expressed with the help of correlation functions for a polarized
electron beam of all orders up to k and the degree of spin polarization. The
form of the correlation function suggests that if the electron beam is not
highly polarized, observing multi-particle correlations should be difficult.
The result can be applied also to chaotic photon beams, the degree of spin
polarization being replaced by the degree of polarization.Comment: 6 pages, 1 eps figure, accepted to Phys. Rev.
Optimized Dynamical Decoupling for Time Dependent Hamiltonians
The validity of optimized dynamical decoupling (DD) is extended to
analytically time dependent Hamiltonians. As long as an expansion in time is
possible the time dependence of the initial Hamiltonian does not affect the
efficiency of optimized dynamical decoupling (UDD, Uhrig DD). This extension
provides the analytic basis for (i) applying UDD to effective Hamiltonians in
time dependent reference frames, for instance in the interaction picture of
fast modes and for (ii) its application in hierarchical
DD schemes with pulses about two perpendicular axes in spin space. to
suppress general decoherence, i.e., longitudinal relaxation and dephasing.Comment: 5 pages, no figure
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