Thin radiating shock layer about a blunt body

Boundary layer flow in thin shock layer about axisymmetric blunt bodies studied by Blasius type series expansion techniqu

Magnetically-induced reconstructions of the ground state in a few-electron Si quantum dot

We report unexpected fluctuations in the positions of Coulomb blockade peaks at high magnetic fields in a small Si quantum dot. The fluctuations have a distinctive saw-tooth pattern: as a function of magnetic field, linear shifts of peak positions are compensated by abrupt jumps in the opposite direction. The linear shifts have large slopes, suggesting formation of the ground state with a non-zero angular momentum. The value of the momentum is found to be well defined, despite the absence of the rotational symmetry in the dot.Comment: 5 pages, 4 figures, accepted to PR

Double-dot charge transport in Si single electron/hole transistors

We studied transport through ultra-small Si quantum dot transistors fabricated from silicon-on-insulator wafers. At high temperatures, 4K<T<100K, the devices show single-electron or single-hole transport through the lithographically defined dot. At T<4K, current through the devices is characterized by multidot transport. From the analysis of the transport in samples with double-dot characteristics, we conclude that extra dots are formed inside the thermally grown gate oxide which surrounds the lithographically defined dot.Comment: 4 pages, 5 figures, to appear in Appl. Phys. Let

Economics of polysilicon processes

Techniques are being developed to provide lower cost polysilicon material for solar cells. Existing technology which normally provides semiconductor industry polysilicon material is undergoing changes and also being used to provide polysilicon material for solar cells. Economics of new and existing technologies are presented for producing polysilicon. The economics are primarily based on the preliminary process design of a plant producing 1,000 metric tons/year of silicon. The polysilicon processes include: Siemen's process (hydrogen reduction of trichlorosilane); Union Carbide process (silane decomposition); and Hemlock Semiconductor process (hydrogen reduction of dichlorosilane). The economics include cost estimates of capital investment and product cost to produce polysilicon via the technology. Sensitivity analysis results are also presented to disclose the effect of major paramentes such as utilities, labor, raw materials and capital investment

Dissolved inorganic carbon cycle in the maximum turbidity zone of the upper Scheldt estuary

The Scheldt Estuary is one of the most polluted macro-tidal European estuaries due to a high anthropogenic pressure around its catchment area. High load of suspended organic matter (with at least two third directly related to human activities) associated to a long residence time within the estuary (three months) contribute to an intense bacterial degradation (Wollast, 1988). The most striking feature of this work, compared to the previous studies carried on the Scheldt (Frankignoulle et al.,1996, 1998; Abril et al., 2000) is the continuous measurement of the CO2 partial pressure of the surface brackish water in the maximum turbidity zone of the inner Scheldt Estuary since November 2002 to nowadays. Our results show that pCO2 in the surface brackish water is outstandingly high, ranging from 2000 to 10000 ppm, which represents up to 2700% of the CO2 atmospheric pressure. CO2 also shows strong meso- and macroscale variabilities and on an annual scale it appears that pCO2 is mainly controlled by temperature and heterotrophy

Generalized Rayleigh and Jacobi processes and exceptional orthogonal polynomials

We present four types of infinitely many exactly solvable Fokker-Planck equations, which are related to the newly discovered exceptional orthogonal polynomials. They represent the deformed versions of the Rayleigh process and the Jacobi process.Comment: 17 pages, 4 figure

A Tunable Anomalous Hall Effect in a Non-Ferromagnetic System

We measure the low-field Hall resistivity of a magnetically-doped two-dimensional electron gas as a function of temperature and electrically-gated carrier density. Comparing these results with the carrier density extracted from Shubnikov-de Haas oscillations reveals an excess Hall resistivity that increases with decreasing temperature. This excess Hall resistivity qualitatively tracks the paramagnetic polarization of the sample, in analogy to the ferromagnetic anomalous Hall effect. The data are consistent with skew-scattering of carriers by disorder near the crossover to localization