Serielle Stückfertigung von Bauteilen aus textilbewehrtem Beton

Serial Batch Production of Building Members Made of Textile Reinforced Concrete Within a research project production techniques were investigated to produce building members made of textile reinforced concrete in a batch production. Laminating, casting, spraying and spinning techniques have been evaluated as well as a combination of these methods. In the beginning the main focus was the production and manufacturing technique with the adjustment of fine grained concrete and fabrics to the respective production technique and the development and choice of distance holders. In order to investigate the manufacturing technique specimens were comprehensively produced by means of selected production techniques. This contains the choice of an adequate production technique, the design of the selected building members, the production of the utilised fabrics as well as the production and testing of the building members. This procedure was carried out for the production of elements of an integrated formwork and spun concrete tubes.     

News: EPA, environmentalists clash over proposal to test contaminated dredged sediments

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News: DOE Environmental Management program awards first basic research grants

Science.     

Design of a high-numerical-aperture miniature microscope objective for an endoscopic fiber confocal reflectance microscope

An endoscopic confocal microscope requires a high-performance, miniaturized microscope objective. We present the design of a miniature water-immersion microscope objective that is approximately 10 times smaller in length than a typical commercial objective. The miniature objective is 7 mm in outer diameter and 21 mm in length (from object to image). It is used in a fiber confocal reflectance microscope. The miniature microscope objective has a numerical aperture of 1.0, a field of view of 250 microm, and a working distance of 450 microm. It delivers diffraction-limited performance at lambda = 1064 nm. Micrometer-level resolution has been experimentally demonstrated.     

Flow cytometric determination of size and complex refractive index for marine particles: comparison with independent and bulk estimates

We advance a method to determine the diameter D and the complex refractive index (n + n'i) of marine particles from flow cytometric measurements of forward scattering, side scattering, and chlorophyll fluorescence combined with Mie theory. To understand better the application of Mie theory with its assumptions to flow cytometry (FCM) measurements of phytoplankton cells, we evaluate our flow cytometric-Mie (FCM-Mie) method by comparing results from a variety of phytoplankton cultures with independent estimates of cell D and with estimates of n and n' from the inversion of bulk measurements. Cell D initially estimated from the FCM-Mie method is lower than independent estimates, and n and n' are generally higher than bulk estimates. These differences reflect lower forward scattering and higher side scattering for single-cell measurements than predicted by Mie theory. The application of empirical scattering corrections improves FCM-Mie estimates of cell size, n, and n'; notably size is determined accurately for cells grown in both high- and low-light conditions, and n' is correlated with intracellular chlorophyll concentration. A comparison of results for phytoplankton and mineral particles suggests that differences in n between these particle types can be determined from FCM measurements. In application to natural mixtures of particles, eukaryotic pico/nanophytoplankton and Synechococcus have minimum mean values of n' in surface waters, and nonphytoplankton particles have higher values of n than phytoplankton at all depths.