Probe studies of silicon p-n junctions

The results of single-probe studies of thick and thin silicon p-n junctions are described. The electric fields in a diode with a p⁺-n junction and in a stabilitron with a p-n junction in the forward and reverse directions are studied. Measurements are made at various currents and temperatures. The p-n junctions are analyzed on the basis of the probe measurements.     

Acrylnitril/Styrol-Copolymer-Emulsionen

Ohne Zusammenfassung     

Magnetic resonance microscopy of biofilm structure and impact on transport in a capillary bioreactor

Microorganisms that colonize surfaces, biofilms, are of significant importance due to their role in medical infections, subsurface contaminant remediation, and industrial processing. Spatially resolved data on the distribution of biomass within a capillary bioreactor, the heterogeneity of the biofilm itself and the impact on transport dynamics for a Staphylococcus epidermidis biofilm in the natural growth state are presented. The data demonstrate the ability of magnetic resonance microscopy to study spatially resolved processes in bacterial biofilms, thus providing a basis for future studies of spatially resolved metabolism and in vivo clinical detection.     

On the flow between two counter-rotating infinite plane disks

This paper studies the boundary-value problem arising from the behaviour of a fluid occupying the region -1≦x≦1 between two rotating disks, rotating about a common axis perpendicular to their planes when the disks are rotating with the same speed Ω₀ but in the opposite sense. The equations which describe the axially symmetric similarity solutions of this problem are $$\varepsilon H^{iv} + HH''' + GG' = 0$$ $$\varepsilon G'' + HG' - H'G = 0$$ with the boundary conditions $$H( \pm 1) = H'( \pm 1) = 0$$ $$G( - 1) = - 1,{\text{ }}G(1) = 1$$ where ?=v/2Ω₀ and v is the kinematic viscosity. The existence of an odd solution is established. This particular solution satisfies many special conditions, for example, G′ (x, ?)>0. Moreover, precise estimates are obtained on the size and behaviour of the solution as ? ↓ 0.     

Dynamics of the solid and liquid phases in dilute sheared Brownian suspensions: irreversibility and particle migration

Magnetic resonance measurements of migration and irreversible dynamics in the capillary shear flow of a Brownian suspension are presented. The results demonstrate the presence of phenomena typically associated with concentrated noncolloidal systems and indicate the role of many body hydrodynamics in dilute Brownian suspension transport. The application of concepts from chaos theory and nonequilibrium statistical mechanics is demonstrated.     

Oxacalixarenes and oxacyclophanes containing 1,8-naphthyridines: a new class of molecular tweezers with concave-surface functionality

The first examples of oxacalix[4]arenes and [1(4)]oxacyclophanes bearing 1,8-naphthyridine units are reported, and these systems function as molecular tweezers containing inner-cavity hydrogen bond acceptors.     

The effect of TiO2 pigment on the performance of paratoluene sulphonic acid catalysed paint systems

The work has highlighted the importance of choosing the correct pigment for paratoluene sulphonic acid (PTSA) catalysed paints. Generally, surface treated TiO₂ grades which are basic in nature resulted in the best optical performance in comparison to acidic surface treated grades. The relative performance of the acidic surface treated grade can be improved by increasing the PTSA level in the paint or by using a resin with a higher acidity level. It is postulated that for these TiO₂ grades, the higher acid levels were found to give better steric repulsion. However, overall, the basic surface treated grade retained the best optical performance in PTSA catalysed paint systems.