Momentum and energy balances for dispersed two-phase flow

Summary The equations of motion and the mechanical energy balances for two-phase flow systems are derived by integration over a volume containing a large number of elements of the dispersed phase.List of symbols A, A boundary of volumes V, V - dA, dA surface element of A, A - A _s boundary of particles in V - dA _s surface element of A _s - F force per unit volume of the system - g –gz=gravity vector - g acceleration by gravity - I unit tensor - p pressure - Q dissipation in the continuous phase - Q _s dissipation in the dispersed phase - R compression work in the continuous phase - R _s compression work in the dispersed phase - t time - u velocity of continuous phase - u _s velocity of dispersed phase - u magnitude of u - u _s magnitude of u _s - V volume in the two-phase system - V part of V occupied by the continuous phase - W work done by F - z vertical coordinate - local volume fraction of the dispersed phase - pI–=stress tensor of the continuous phase - _s turbulent particle stress tensor - density of the continuous phase - _s density of the dispersed phase - shearing-stress tensor of the continuous phase - _s turbulent particle shearing-stress tensor - nabla operator - u, u _s velocity gradient tensor - substantial derivative (Shell Internationale Research Maatschappij N.V.)(Bataafse Internationale Petroleum Maatschappij N.V.)     

Zur Bestimmung des Adrenalins

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Nachweis und Bestimmung der Benzo?s?ure in Lebensmitteln

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Femtosecond dynamics in ferromagnetic metals investigated with soft x-ray resonant emission

We present measurements of the magnetic circular dichroism in x-ray resonant emission in the perpendicular geometry (circularly polarized x rays at normal incidence to the magnetization) for L(2,3) the absorption region in Fe, Co, and Ni metal. The results show that spin-dependent screening of the core hole takes place within the scattering time scale, which is supported by the absence of the effect in ionic systems. This allows an assessment of the time scale for the screening process (up to a few femtoseconds). The process is almost complete within the scattering time for Fe and Co, but this is not the case for the narrow band metal Ni which shows a much slower dynamics.     

Plasma-aided hydrogenation and Al-doping: Increasing the conductivity and optical transparency of ZnO transparent conducting oxide

Plasma-assisted magnetron sputtering with varying ambient conditions has been utilised to deposit Al-doped ZnO (AZO) transparent conductive thin films directly onto a glass substrate at a low substrate temperature of 400 °C. The effects of hydrogen addition on electrical, optical and structural properties of the deposited AZO films have been investigated using X-ray diffractometry (XRD), scanning electron microscopy (SEM), Hall effect measurements and UV-vis optical transmission spectroscopy. The results indicate that hydrogen addition has a remarkable effect on the film transparency and conductivity with the greatest effects observed with a hydrogen flux of approximately 3 sccm. It has been demonstrated that the conductivity and the average transmittance in the visible range can increase simultaneously contrary to the effects observed by other authors. In addition, hydrogen incorporation further leads to the absorption edge shifting to a shorter wavelength due to the Burstein-Moss effect. These results are of particular relevance to the development of the next generation of optoelectronic and photovoltaic devices based on highly transparent conducting oxides with controllable electronic and optical properties.     

Inventory strategies for systems with fast remanufacturing

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