Germanium nanocrystals embedded in silicon dioxide for floating gate memory devices

Metal-oxide-semiconductor (MOS) capacitors with tri-layer structure consisting of rf magnetron sputtered grown germanium (Ge) nanocrystals (NCs) and silicon dioxide (SiO2) layers sandwiched between thermally grown tunnel and sputtered grown cap oxide layers of SiO2 were fabricated on p-Si substrates. Plane view transmission electron micrographs revealed the formation of spherically shaped and uniformly distributed Ge NCs. The optical and electronic characteristics of tri-layer structures were studied through photoluminescence (PL) spectroscopy and capacitance-voltage (C-V) measurements, respectively. Frequency dependent electrical properties of the structures have been studied. The optical emission characteristics support the confinement of the carriers in Ge NCs embedded in oxide matrices. An anticlockwise hysteresis in C-V characteristics suggests electron injection and trapping in Ge NCs. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2785

Chemical extraction and optimization of intracellular β-galactosidase production from the bacterium Arthrobacter oxydans using Box-Behnken design of response surface methodology

Present study demonstrated the isolation of most promising β-galactosidase producing bacterial strain SB from soil. Morphological, biochemical, and 16s rRNA sequence analysis identified the bacterial strain as Arthrobacter oxydans. Several chemicals, including SDS, Triton X-100, Tween 20, isoamyl alcohol, and toluene-acetone mixture, were applied for extraction of intracellular β-galactosidase from the bacterial strain Arthrobacter oxydans. Among these, Tween 20 was recorded to be most effective. Role of pH, temperature, and shaker speed on production of β-galactosidase was evaluated using Box-Behnken design of response surface methodology. According to Box-Behnken analysis, optimum production of β-galactosidase (21.38 U (mg–1 protein)) is predicted at pH 6.76, temperature 36.1 °C, and shaker speed 121.37 r.p.m. The parameters are validated with the nearest value

Multi Objective Directed Bee Colony Optimization for Economic Load Dispatch With Enhanced Power Demand and Valve Point Loading

Earlier economic emission dispatch methods for optimizing emission level comprising carbon monoxide, nitrous oxide and sulpher dioxide in thermal generation, made use of soft computing techniques like fuzzy,neural network,evolutionary programming,differential evolution and particle swarm optimization etc..The above methods incurred comparatively more transmission loss.So looking into the nonlinear load behavior of unbalanced systems following differential load pattern prevalent in tropical countries like India,Pakistan and Bangladesh etc.,the erratic variation of enhanced power demand is of immense importance which is included in this paper vide multi objective directed bee colony optimization with enhanced power demand to optimize transmission losses to a desired level.In the current dissertation making use of multi objective directed bee colony optimization with enhanced power demand technique the emission level versus cost of generation has been displayed vide figure-3 & figure-4 and this result has been compared with other dispatch methods using valve point loading(VPL) and multi objective directed bee colony optimization with & without transmission loss

Improved Temperature Performance of 1.31-mu/m Quantum Dot Lasers by Optimized Ridge Waveguide Design

In this letter, we demonstrate the importance of the fabricated device structure for the external differential efficiency, threshold current density, and maximum operating temperature for ground state operation of a 1.31-mu/m quantum dot laser. The introduction of a shallow ridge etch design and selective electroplating of the gold bondpads is demonstrated to offer improved performance in comparison to a deep ridge etch design with thinner evaporated gold bondpads

Enhanced orbital electron-capture nuclear decay rate in compact medium

The eigenstate energies of an atom increase under spatial confinement and this effect should also increase the electron density of the orbital electrons at the nucleus thus increasing the decay rate of an electron-capturing radioactive nucleus. We have observed that the orbital electron capture rates of 109In and 110Sn increased by (1.00+-0.17)% and (0.48+-0.25)% respectively when implanted in the small Au lattice versus large Pb lattice. These results have been understood because of the higher compression experienced by the large radioactive atoms due to the spatial confinement in the smaller Au lattice.Comment: 30 pages, 3 Figures, 2 Table

Analysis of Hysteresis Loops of 316L(N) Stainless Steel under Low Cycle Fatigue Loading Conditions

AbstractLow cycle fatigue tests were carried out on 316 L(N) stainless steel at room temperature employing strain amplitudes ranging from ± 0.3 to ±1.0% and a strain rate of 3×10−3s−1. The material showed initial hardening for a few cycles followed by prolonged softening, saturation and final failure. The fatigue life was found to decrease with increase in strain amplitude. The analysis of stable hysteresis loops showed non-Masing behaviour for this material. The elasto-plastic response of the material under cyclic loading was characterized taking into account isotropic and kinematic hardening occurring during cycling. The material parameters were obtained from the experimental hysteresis loops and cyclic stress response of the material. Finite element analysis of elasto-plastic deformation was carried out to obtain the stabilized hysteresis loop and cyclic stress response of the material. The predicted hysteresis loops showed good agreement with experimental results. The low cycle fatigue life prediction was carried out based on plastic strain energy dissipation with cycling

Indian Coals vis-a-vis Spontaneous Heating Problems

The paper highlights the alarming problem of spontaneous heating in mines so that immediate remedies can be identified and implemented. The status of spontaneous heating in the last four decades has been summarized showing the changing trend of spontaneous heating occurrences in India. The paper also deals with some new methods of dealing mine fires which so far have not been implemented in India but have great potential

Coal mine fires - hazards and modern control techniques

Fires have long been recognized as hazards associated with coal mining. Coal mine fire causes economic losses by virtue of loss of coal and coal winning machinery. Environmental problems at surface and underground due to coal mine fire are discussed in terms of production of noxious, toxic gases, global warming and fire damp explosion. Social and health problems due to mine fire are dealt with. An account of modern techniques like water mist technology, remote sensing and infusion of carbon dioxide are also given

Viscosity in spherically symmetric accretion

The influence of viscosity on the flow behaviour in spherically symmetric accretion, has been studied here. The governing equation chosen has been the Navier-Stokes equation. It has been found that at least for the transonic solution, viscosity acts as a mechanism that detracts from the effectiveness of gravity. This has been conjectured to set up a limiting scale of length for gravity to bring about accretion, and the physical interpretation of such a length-scale has been compared with the conventional understanding of the so-called "accretion radius" for spherically symmetric accretion. For a perturbative presence of viscosity, it has also been pointed out that the critical points for inflows and outflows are not identical, which is a consequence of the fact that under the Navier-Stokes prescription, there is a breakdown of the invariance of the stationary inflow and outflow solutions -- an invariance that holds good under inviscid conditions. For inflows, the critical point gets shifted deeper within the gravitational potential well. Finally, a linear stability analysis of the stationary inflow solutions, under the influence of a perturbation that is in the nature of a standing wave, has indicated that the presence of viscosity induces greater stability in the system, than has been seen for the case of inviscid spherically symmetric inflows.Comment: 7 pages. Minor changes made in the version published in MNRA