In this work we present the evaluation results of our 3D sonar camera system. The system consists of a matrix antenna array with 1024 single transducer elements and our in house developed DiPhAS sonar beamformer - a 128 channel FPGA-based beamforming system with a 1:8 multiplexing device for each channel. The system is designed to be applicable to ROV and AUV systems for real-time volumetric imaging in a deep sea environment. Defocused excitation of the transducer array is used to achieve a sound field opening angle of up to 40° in lateral and elevational direction. The antenna's sound field can be adjusted electronically in order to increase either the imaged area or the image contrast in a specific area of interest. Different filter algorithms working on a raw data basis have been implemented in order to suppress image artifacts which occur during the reconstruction process. Measurements on different phantoms have been performed in order to prove the real-time imaging as well as spatial resolution capabilities of the camera system

A new method for the nuclear magnetic resonance (NMR) surface relaxivity calibration in hydrated cement samples is proposed. This method relies on a combined analysis of 28-d hydrated tricalcium silicate samples by scanning electron microscopy (SEM) image analysis and 1H-time-domain (TD)-NMR relaxometry. Pore surface and volume data for interhydrate pores are obtained from high resolution SEM images on surfaces obtained by argon broad ion beam sectioning. These data are combined with T2 relaxation times from 1H-TD-NMR to calculate the systems surface relaxivity according to the fast exchange model of relaxation. This new method is compared to an alternative method that employs sequential drying to calibrate the systems surface relaxivity.

Object recognition, advanced distance measurements and other inspection scenarios have an increasing demand in versatile airborne ultrasonic phased arrays for acoustic scanning without moving parts. Based on cellular polymer film with high piezoelectric effect we have realized an array structure with a pitch of 0.5 mm and element length of 10 mm. The working frequency of the material was measured to 250 kHz. From pointspread simulation with the small ratio of pitch/wavelength of 0.35 we could expect good beam steering and focusing characteristics. A first test array was realized and characterized. There was good agreement between measurement results and simulations. Additionally a low frequency electronic beamformer system was developed for generating the first B-image of an airborne phased array. Measurements showed that cellular polymer is a well suitable material for airborne applications. It can easily be structured to the desired shape. It allows especially the realization of Phased Arrays for applications like surface or profile measurement, access control, attendance check, robot guidance etc.. New airborne array types like linear, phased, curved or circular arrays are now possible. Also single element transducers with varying apertures (rectangular, oval), shaped apertures (focusing (line-or point-focusing), defocusing) or combinations of both are possible.

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This paper presents the state of the art in positively guided transport systems for underground mines and gives an outlook on some future developments that are just about to enter the testing phase. Diesel‐hydraulic self‐propelled drives with positive‐engagement power transmission are currently indispensable, especially in mines with steeper stretches to cope with, ever higher individual loads and high transport capacities. A prerequisite for exploiting the capacity of these transport systems is the online communication of all relevant information and its use for process optimisation. From this foundation, the future will see the increased use of intelligent control systems, which will contribute to a further increase in the safety and efficiency of underground transport. Der Beitrag stellt den letzten Stand der Technik der zwangsgeführten Transportsysteme für untertägige Bergwerke vor und gibt einen Ausblick auf künftige Weiterentwicklungen, die unmittelbar vor der Erprobungsphase stehen. Dieselhydraulische Eigenantriebe mit formschlüssiger Kraftübertragung sind derzeit insbesondere in Bergwerken mit stärker geneigten Strecken zur Bewältigung immer höherer Einzellasten und hoher Transportkapazitäten unumgänglich. Voraussetzung für die Ausnutzung der Leistungsfähigkeit dieser Transportsysteme ist die online‐Datenübertragung aller relevanten Informationen und deren Verwendung zur Prozessoptimierung. Darauf aufbauend werden zukünftig intelligente Steuerungssysteme vermehrt eingesetzt, die zu einer weiteren Erhöhung der Sicherheit und Effizienz des untertägigen Transports beitragen.