2,288 research outputs found
Thermal annealing behaviour on electrical properties of Pd/Ru Schottky contacts on n-type GaN
We have investigated the electrical properties of Pd/Ru Schottky contacts on n-GaN as a function of annealing temperature by current-voltage (I-V) and capacitance-voltage (C-V) measurements. The Schottky barrier height of the as-deposited Pd/Ru contact is found to be 0.67 eV (I-V) and 0.79 eV (C-V), respectively. Measurements showed that the Schottky barrier height increased from 0.68 eV (I-V) and 0.80 eV (C-V) to 0.80 eV (I-V) and 0.96 eV (C-V) as the annealing temperature is varied from 200 °C to 300 °C. Upon annealing at 400 °C and 500 °C, the Schottky barrier height decreased to 0.73 eV (I-V) and 0.85 eV (C-V) and 0.72 eV (I-V) and 0.84 eV (C-V), respectively. It is noted that the barrier height further decreased to 0.59 eV (I-V) and 0.72 eV (C-V) when the contact is annealed at 600 °C. The change of Schottky barrier heights and ideality factors with annealing temperature may be due to the formation of interfacial compounds at the Ru/Pd/n-GaN interface.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2788
Aquaculture vis-a-vis agriculture
The effect of aquaculture, especially shrimp farming, on agriculture has caused heated debate among aquaculturists, agriculturists, and non-governmental organizations. As data on the negative impact of shrimp farming on adjacent rice fields are not available, a study was undertaken in rice fields skirting three shrimp farms: a semi-intensive farm; an extensive farm; and a semi-intensive farm with a buffer zone. The buffer zone was found to be helpful in preventing salinization of the adjacent agricultural fields and the Electrical Conductivity (EC) values (less than 1) reported were found to be harmless to the rice crop. Thus, aquaculture and agriculture can coexist in coastal areas if there are buffer zones in between
Chiral Lagrangian and spectral sum rules for dense two-color QCD
We analytically study two-color QCD with an even number of flavors at high
baryon density. This theory is free from the fermion sign problem. Chiral
symmetry is broken spontaneously by the diquark condensate. Based on the
symmetry breaking pattern we construct the low-energy effective Lagrangian for
the Nambu-Goldstone bosons. We identify a new epsilon-regime at high baryon
density in which the quark mass dependence of the partition function can be
determined exactly. We also derive Leutwyler-Smilga-type spectral sum rules for
the complex eigenvalues of the Dirac operator in terms of the fermion gap. Our
results can in principle be tested in lattice QCD simulations.Comment: 24 pages, 1 table, no figur
A BCS Gap on the Lattice
Monte Carlo simulations of the 3+1 dimensional NJL model are performed with
baryon chemical potential mu>0. For mu>Sigma_0, the constituent quark mass in
vacuum, chiral symmetry is restored and a diquark condensate forms. We
analyse the fermion propagator and find evidence for particle-hole mixing in
the vicinity of the Fermi surface and an energy gap Delta>0, both of which
provide evidence for superfluidity at high baryon density induced by a BCS
mechanism.
At (mu a)=0.8 the ratio between the BCS gap and the vacuum quark mass is
Delta/Sigma_0=0.15(2).Comment: 3 pages, 3 figures, Lattice2003(nonzero
Indian Ocean surface winds from NCMRWF analysis as compared to QuikSCAT and moored buoy winds
The quality of the surface wind analysis at the National Centre for Medium Range Weather Forecasts (NCMRWF), New Delhi over the tropical Indian Ocean and its improvement in 2001 are examined by comparing it within situ buoy measurements and satellite derived surface winds from NASA QuikSCAT satellite (QSCT) during 1999, 2000 and 2001. The NCMRWF surface winds suffered from easterly bias of 1.0-1.5 ms-1 in the equatorial Indian Ocean (IO) and northerly bias of 2.0-3.0 ms-1 in the south equatorial IO during 1999 and 2000 compared to QSCT winds. The amplitude of daily variability was also underestimated compared to that in QSCT. In particular, the amplitude of daily variability of NCMRWF winds in the eastern equatorial IO was only about 60% of that of QSCT during 1999 and 2000. The NCMRWF surface winds during 2001 have significantly improved with the bias of the mean analyzed winds considerably reduced everywhere bringing it to within 0.5 ms-1 of QSCT winds in the equatorial IO. The amplitude and phase of daily and intraseasonal variability are very close to that in QSCT almost everywhere during 2001. It is shown that the weakness in the surface wind analysis during 1999 and 2000 and its improvement in 2001 are related to the weakness in simulation of precipitation by the forecast model in the equatorial IO and its improvement in 2001
Emergency TeleOrthoPaedics m-health system for wireless communication links
For the first time, a complete wireless and mobile emergency TeleOrthoPaedics system with field trials and expert opinion is presented. The system enables doctors in a remote area to obtain a second opinion from doctors in the hospital using secured wireless telecommunication networks. Doctors can exchange securely medical images and video as well as other important data, and thus perform remote consultations, fast and accurately using a user friendly interface, via a reliable and secure telemedicine system of low cost. The quality of the transmitted compressed (JPEG2000) images was measured using different metrics and doctors opinions. The results have shown that all metrics were within acceptable limits. The performance of the system was evaluated successfully under different wireless communication links based on real data
Strangeness in Neutron Stars
It is generally agreed on that the tremendous densities reached in the
centers of neutron stars provide a high-pressure environment in which several
intriguing particles processes may compete with each other. These range from
the generation of hyperons to quark deconfinement to the formation of kaon
condensates and H-matter. There are theoretical suggestions of even more exotic
processes inside neutron stars, such as the formation of absolutely stable
strange quark matter. In the latter event, neutron stars would be largely
composed of strange quark matter possibly enveloped in a thin nuclear crust.
This paper gives a brief overview of these striking physical possibilities with
an emphasis on the role played by strangeness in neutron star matter, which
constitutes compressed baryonic matter at ultra-high baryon number density but
low temperature which is no accessible to relativistic heavy ion collision
experiments.Comment: 16 pages, 5 figures, 3 tables; Accepted for publication in the
Proceedings of the International Workshop on Astronomy and Relativistic
Astrophysics (IWARA) 2005, Int. J. Mod. Phys.
Hadron-quark mixed phase in hyperon stars
We analyze the different possibilities for the hadron-quark phase transition
occurring in beta-stable matter including hyperons in neutron stars. We use a
Brueckner-Hartree-Fock approach including hyperons for the hadronic equation of
state and a generalized MIT bag model for the quark part. We then point out in
detail the differences between Maxwell and Gibbs phase transition constructions
including the effects of surface tension and electromagnetic screening. We find
only a small influence on the maximum neutron star mass, whereas the radius of
the star and in particular its internal structure are more affected.Comment: 11 pages, 9 figure
Charge diffusion constant in hot and dense hadronic matter - A Hadro-molecular-dynamic calculation
We evaluate charge diffusion constant of dense and hot hadronic matter based
on the molecular dynamical method by using a hadronic collision generator which
describes nuclear collisions at energies 10 < E < 100 GeV/A and satisfies
detailed balance at low temperatures (T < 200 MeV). For the hot and dense
hadronic matter of the temperature range, 100 < T < 200 MeV and baryon number
density, 0.16 < nB < 0.32 fm^-3, charge diffusion constant D gradually
increases from 0.5 fm c to 2 fm c with temperature and is almost independent of
baryon number density. Based on the obtained diffusion constant we make simple
discussions on the diffusion of charge fluctuation in ultrarelativistic nuclear
collisions.Comment: 13 pages, 4 figure
- …