19,257 research outputs found
Dielectric relaxation and Charge trapping characteristics study in Germanium based MOS devices with HfO2 /Dy2O3 gate stacks
In the present work we investigate the dielectric relaxation effects and
charge trapping characteristics of HfO2 /Dy2O3 gate stacks grown on Ge
substrates. The MOS devices have been subjected to constant voltage stress
(CVS) conditions at accumulation and show relaxation effects in the whole range
of applied stress voltages. Applied voltage polarities as well as thickness
dependence of the relaxation effects have been investigated. Charge trapping is
negligible at low stress fields while at higher fields (>4MV/cm) it becomes
significant. In addition, we give experimental evidence that in tandem with the
dielectric relaxation effect another mechanism- the so-called Maxwell-Wagner
instability- is present and affects the transient current during the
application of a CVS pulse. This instability is also found to be field
dependent thus resulting in a trapped charge which is negative at low stress
fields but changes to positive at higher fields.Comment: 27pages, 10 figures, 3 tables, regular journal contribution (accepted
in IEEE TED, Vol.50, issue 10
Multiplex evaluation of influenza neutralizing antibodies with potential applicability to in-field serological studies
The increased number of outbreaks of H5 and H7 LPAI and HPAI viruses in poultry has major public and animal health implications. The continuous rapid evolution of these subtypes and the emergence of new variants influence the ability to undertake effective surveillance.
Retroviral pseudotypes bearing influenza haemagglutinin (HA) and neuraminidase (NA) envelope glycoproteins represent a flexible platform for sensitive, readily standardized influenza serological assays. We describe a multiplex assay for the study of neutralizing antibodies that are directed against both influenza H5 and H7 HA. This assay permits the measurement of neutralizing antibody responses against two antigenically distinct HAs in the same serum/plasma sample thus increasing the amount and quality of serological data that can be acquired from valuable sera. Sera obtained from chickens vaccinated with a monovalent H5N2 vaccine, chickens vaccinated with a bivalent H7N1/H5N9 vaccine, or turkeys naturally infected with an H7N3 virus were evaluated in this assay and the results correlated strongly with data obtained by HI assay. We show that pseudotypes are highly stable under basic cold-chain storage conditions and following multiple rounds of freeze-thaw. We propose that this robust assay may have practical utility for in-field sero-surveillance and vaccine studies in resource-limited regions worldwide
Socio-demographic differences of disability prevalence among the population aged 60 years and over in Bangladesh
This study aims to delineate the sociodemographic differences in disability prevalence across the population aged 60 years and over in Bangladesh, and to investigate the association of factors with reporting disability in later life. A microdata sample for those aged 60 years or over from the Census of Bangladesh 2011 was used where disability was assessed with a self-reported single response question. Logistic regression models were performed separately for men and women. Results reveal that the disability prevalence rate increased sharply with age, and it was higher among older women (5.2%) compared to men (4.8%). Physical and vision disabilities were the two categories with the highest prevalence of reported disabilities, with a higher prevalence of physical disability among men and vision disability among women. Being older, female, currently not in marital partnership, and having a lower educational attainment, not being employed, living alone, and residing in the rural areas were significantly associated with reporting disability in later life. The higher prevalence of disability among older women, those who are illiterate, and those residing in rural areas highlights the need for policies prioritising these groups. Special attention should also be given to those who are currently not in marital partnership, particularly women who are living alone
Who Are Today’s Farmers and What are Their Educational Needs?
Labor and Human Capital, Teaching/Communication/Extension/Profession,
High yield fusion in a Staged Z-pinch
We simulate fusion in a Z-pinch; where the load is a xenon-plasma liner
imploding onto a deuterium-tritium plasma target and the driver is a 2 MJ, 17
MA, 95 ns risetime pulser. The implosion system is modeled using the dynamic,
2-1/2 D, radiation-MHD code, MACH2. During implosion a shock forms in the Xe
liner, transporting current and energy radially inward. After collision with
the DT, a secondary shock forms pre-heating the DT to several hundred eV.
Adiabatic compression leads subsequently to a fusion burn, as the target is
surrounded by a flux-compressed, intense, azimuthal-magnetic field. The
intense-magnetic field confines fusion -particles, providing an
additional source of ion heating that leads to target ignition. The target
remains stable up to the time of ignition. Predictions are for a neutron yield
of and a thermonuclear energy of 84 MJ, that is, 42 times
greater than the initial, capacitor-stored energy
A tight-binding model for MoS monolayers
We propose an accurate tight-binding parametrization for the band structure
of MoS monolayers near the main energy gap. We introduce a generic and
straightforward derivation for the band energies equations that could be
employed for other monolayer dichalcogenides. A parametrization that includes
spin-orbit coupling is also provided. The proposed set of model parameters
reproduce both the correct orbital compositions and location of valence and
conductance band in comparison with ab initio calculations. The model gives a
suitable starting point for realistic large-scale atomistic electronic
transport calculations.Comment: 35 pages, 8 figure
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