Characterization of polyacrylonitrile ultrafiltration membranes

Various methods have been used to characterize ultrafiltration membranes, such as gas flux measurements, (field emission) scanning electron microscopy, permporometry and liquid-liquid displacement. Significant differences in the pore size distributions determined from permporometry and liquid-liquid displacement were found

Analysis of reinforced concrete structures with occurrence of discrete cracks at arbitrary positions

A nonlinear analysis of in-plane loaded plates is presented, which eliminates the disadvantages of the smeared crack approach. The elements used and the computational method are discussed. An example is shown in which one or more discrete cracks are dominant

Towards linking perception research and image quality

Image quality as a general notion relates both to elementary and to complex visual functions. In this paper we deal with a few of them, which correspond to some lines of research at our Institute. We start with threshold predictions in time and space domains by means of elementary response functions, which have been recently developed considerably, although full generalization has not yet been achieved. As to suprathreshold stimuli, the responses of subjects usually have to be scaled. Here we deal with some problems connected with scaling techniques. After a brief discussion of the applicability of notions on visual conspicuity and visual search to image quality problems, we finally discuss reading from alphanumeric displays