Design and Production of Thin and Small Micro Strips

This article describes a recently started research project about the rolling of small and very thin strip, or in other words the production of micro strip using flat rolling processes. Main subject of the article is the finite element simulation of the production process and its validation. First the practical relevance of micro strip and its production process are presented. Furthermore the scaling effects which miniaturisation brings with it are introduced. Determination and consideration of the size effects are essentials in order to make optimisation possible. It is proposed to determine the size effects in the flow curve with a miniaturised multi‐layer plane strain compression test. The simulation will be done on a continuum base which includes the determined size effects out of the multi‐layer plane strain compression test. Finally a comparison of the FEM‐simulation results (rolling force, cross sectional geometry) with real processes validates the modified finite element simulation.     

FDTD-Modelling of Dispersive Nonlinear Ring Resonators: Accuracy Studies and Experiments

The accuracy of nonlinear finite-difference time-domain (FDTD) methods is investigated by modeling nonlinear optical interaction in a ring resonator. We have developed a parallelized 3-D FDTD algorithm which incorporates material dispersion, chi⁽³⁾-nonlinearities and stair-casing error correction. The results of this implementation are compared with experiments, and intrinsic errors of the FDTD algorithm are separated from geometrical uncertainties arising from the fabrication tolerances of the device. A series of progressively less complex FDTD models is investigated, omitting material dispersion, abandoning the stair-casing error correction, and approximating the structure by a 2-D effective index model. We compare the results of the different algorithms and give guidelines as to which degree of complexity is needed in order to obtain reliable simulation results in the linear and the nonlinear regime. In both cases, incorporating stair-casing error correction and material dispersion into a 2-D effective index model turns out to be computationally much cheaper and more effective than performing a fully three-dimensional simulation without these features     

Binary common-ion alkali halide mixtures thermodynamic analysis of solid-liquid phase diagrams i. systems with negligible solid miscibility application of the extxd/sivamin method

Solid-liquid phase diagrams of 15 binary common-ion alkali halide mixtures, showing negligible solid miscibility, have been analyzed using the EXTXD/SIVAMIN method. The principles of and the philosophy behind the method, which permits the simultaneous derivation of the excess enthalpy and excess entropy functions from a single TX phase diagram, are discussed. The significance of the results is investigated by recalculating the phase diagrams and by comparing the excess enthalpy functions with experimental heats of mixing.     

TRANSPORTATION, FRONTIER EFFECTS AND REGIONAL DEVELOPMENT IN THE COMMON MARKET

ABSTRACT In tins paper the locational effects of introducing High Speed Railways in France, the Benelux and West Germany art estimated, together with the spatial impacts of a far reaching reduction of the internal borders of the EEC. To this aim a multisectoral potentials model is developed. It estimates the zero-sum kind of spatial redistribution effects that are due to changes in relative regional accessibility, as well as the generative net growth effects that are due to increases in market areas and the conseguent economies of scale. Empirically, surprising spatial differences in such effects are found.     

Biophotonic sensors with integrated Si3N4-organic hybrid (SiNOH) lasers for point-of-care diagnostics

Early and efficient disease diagnosis with low-cost point-of-care devices is gaining importance for personalized medicine and public health protection. Within t...     

Book reviews

The Annals of Regional Science -     

Sperm oil replacements from selectively hydrogenated soybean and linseed esters: Special lubricants

Soybean and linseed oils were selectively hydroenated with copper-on-silica gel catalyst. The linolenate content of the oils was reduced to diene and monoene with no appreciable increase in saturates. Hydrogenated soybean oils contained 68–76% monoene, 11–18% diene, 0% conjugated diene and triene, 1–6% conjugatable diene, 0–0.3% conjugatable triene, and 23–40% isolatedtrans double bonds. Hydrogenated linseed oils contained 44–54% monoene, 35–45% diene, 0% conjugated diene and triene, 0–7% conjugatable diene, 0–02% conjugatable triene, and 44–59% isoaltedtrans double bonds. Esters of fatty acids, derived from these selectively hydrogenated oils, were prepared with trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol, ethylene glycol, C₁₈ saturated cyclic alcohols, primary C₁₂–C₁₈ saturated (nC₁₂, nC₁₄, nC₁₆, nC₁₈) alcohol, and primary C₁₆–C₁₈ saturated (nC₁₆, nC₁₈) alcohol blends. Measurements of viscosities and of smoke, flash, and fire points indicate that these esters are possible replacements for sperm oil. Certain of them, after sulfurization, also have potential as extreme pressure lubricant additives. Presented at the AOCS meeting in Philadelphia, September 1974.     

Cavernous malformations: from frame-based to frameless stereotactic localization

AIM: To determine the change in use of a day surgery unit over a 21-year period. DESIGN: Retrospective analysis. SETTING: The day surgery unit within a central London dental hospital. MATERIALS: The operating and anaesthetic records of surgical activity in 1973, 1983, 1993 and 1994. RESULTS: A six-fold increase in the total number of dentoalveolar procedures performed was demonstrated during the period studied. However, these procedures represented only 77.6% of surgical activity in 1994 compared with 98.9% in 1973. CONCLUSIONS: Day case surgery appears to be advantageous to patients, clinicians, hospital managers and purchasing authorities. The development of more specialist day case services and facilities within "dental centres' is proposed as a means of ensuring that the specialty is able to adapt to the changing patterns of health care in the future.