49 research outputs found
Landau level mixing by full spin-orbit interactions
We study a two-dimensional electron gas in a perpendicular magnetic field in
the presence of both Rashba and Dresselhaus spin-orbit interactions. Using a
Bogoliubov transformation we are able to write an approximate formula for the
Landau levels, thanks to the simpler form of the resulting Hamiltonian. The
exact numerical calculation of the energy levels, is also made simpler by our
formulation. The approximate formula and the exact numerical results show
excellent agreement for typical semiconductors, especially at high magnetic
fields. We also show how effective Zeeman coupling is modified by spin-orbit
interactions.Comment: 5 pages, 5 figure
Effects of different packaging methods on microbial, [chemical] and sensory properties of Nile tilapia (Oreochromis niloticus Linnaeus, 1758) fillets during refrigerator storage
The effect of three different packaging methods including Modified Atmosphere Packaging (MAP), Vacuum Packaging and normal Packaging was investigated on the quality of Nile tilapia fresh fillets stored in the refrigerator's temperature. The packaged samples were examined for 10 days with regard to the changes in chemical (TVN, PV, pH), microbial (total viable count) and sensory evaluations. The results indicated that the samples packed in MAP condition had higher quality than that of other methods at the end of the storage period. In addition, the slower destructive impacts and microbial growth was observed in MAP. The results of present study suggest that packaging tilapia under MAP conditions results in the increase in the durability, storing, and distribution period for fillets
Edge States of Monolayer and Bilayer Graphene Nanoribbons
On the basis of tight-binding lattice model, the edge states of monolayer and
bilayer graphene nanoribbons (GNRs) with different edge terminations are
studied. The effects of edge-hopping modulation, spin-orbital coupling (SOC),
and bias voltage on bilayer GNRs are discussed. We observe the following: (i)
Some new extra edge states can be created by edge-hopping modulation for
monolayer GNRs. (ii) Intralayer Rashba SOC plays a role in depressing the band
energy gap opened by intrinsic SOC for both monolayer and bilayer GNRs.
An almost linear dependent relation, i.e., , is found. (iii)
Although the bias voltage favors a bulk energy gap for bilayer graphene without
intrinsic SOC, it tends to reduce the gap induced by intrinsic SOC. (iv) The
topological phase of the quantum spin Hall effect can be destroyed completely
by interlayer Rashba SOC for bilayer GNRs.Comment: 6 pages, 6 figure
Anisotropic superconductivity of niobium based on its response to non-magnetic disorder
Niobium is one of the most studied superconductors, both theoretically and
experimentally. It is tremendously important for applications, and it has the
highest superconducting transition temperature, K, of all pure
metals. In addition to power applications in alloys, pure niobium is used for
sensitive magneto-sensing, radio-frequency cavities, and, more recently, as
circuit metallization layers in superconducting qubits. A detailed
understanding of its electronic and superconducting structure, especially its
normal and superconducting state anisotropies, is crucial for mitigating the
loss of quantum coherence in such devices. Recently, a microscopic theory of
the anisotropic properties of niobium with the disorder was put forward. To
verify theoretical predictions, we studied the effect of disorder produced by
3.5 MeV proton irradiation of thin Nb films grown by the same team and using
the same protocols as those used in transmon qubits. By measuring the
superconducting transition temperature and upper critical fields, we show a
clear suppression of by potential (non-magnetic) scattering, which is
directly related to the anisotropic order parameter. We obtain a very close
quantitative agreement between the theory and the experiment
Thermo-structural analysis and electrical conductivity behavior of epoxy/metals composites
Herbivory of an invasive slug in a model grassland community can be affected by earthworms and mycorrhizal fungi
Randomized clinical trials of dental bleaching – Compliance with the CONSORT Statement: a systematic review
Identification of Sand flies of the Subgenus Larroussius based on Molecular and Morphological Characters in North Western Iran
Background: The adult female sand flies (Diptera: Psychodidae) of the subgenus Larroussius are important vectors of Leishmania infantum (Kinetoplastida: Tripanosomatidae) in Meshkinshahr district, Northwest of Iran. Four Phlebotomus (Larroussius) species are present in this area, i.e. Phlebotomus (Larroussius) kandelakii, P. (La.) major, P. (La.) perfiliewi and P. (La.) tobbi. The objective of the present study was to identify and distinguish the females of P. perfiliewi, P. major and P. tobbi, in this district.
Methods: Adult sand flies were collected with sticky papers, CDC light traps, and aspirator in 2006. Individual sand flies of this four species from thirty different locations were characterized morphologically and by comparative DNA sequences analyses of a fragment of mitochondrial gene Cytochrome b (Cyt b) and nuclear gene Elongation Factor 1- alpha (EF-1α). PCR amplification was carried out for all three species P. major, P. perfiliewi and P. tobbi in the subgenus Larroussius.
Results: Phylogenetic analyses of P. major populations in this study displayed two different populations and genetic diversity. Spermathecal segment number, pharyngeal armature and other morphological characters of these three species were examined and found to present consistent interspecific differences.
Conclusion: According to our findings, the phylogeny of Cyt b and EF-1α haplotypes confirms the relationships between P. major, P. tobbi and P. perfiliewi as already defined by their morphological similarities