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Author: Müller, Franz × DDC: 660 ×

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    Comparison of novel semi-airborne electromagnetic data with multi-scale geophysical, petrophysical and geological data from Schleiz, Germany
    (Amsterdam [u.a.] : Elsevier Science, 2020) Steuer, Annika; Smirnova, Maria; Becken, Michael; Schiffler, Markus; Günther, Thomas; Rochlitz, Raphael; Yogeshwar, Pritam; Mörbe, Wiebke; Siemon, Bernhard; Costabel, Stephan; Preugschat, Benedikt; Ibs-von Seht, Malte; Zampa, Luigi Sante; Müller, Franz
    In the framework of the Deep Electromagnetic Sounding for Mineral EXploration (DESMEX) project, we carried out multiple geophysical surveys from regional to local scales in a former mining area in the state of Thuringia, Germany. We prove the applicability of newly developed semi-airborne electromagnetic (EM) systems for mineral exploration by cross-validating inversion results with those of established airborne and ground-based investigation techniques. In addition, supporting petrophysical and geological information to our geophysical measurements allowed the synthesis of all datasets over multiple scales. An initial regional-scale reconnaissance survey was performed with BGR's standard helicopter-borne geophysical system deployed with frequency-domain electromagnetic (HEM), magnetic and radiometric sensors. In addition to geological considerations, the HEM results served as base-line information for the selection of an optimal location for the intermediate-scale semi-airborne EM experiments. The semi-airborne surveys utilized long grounded transmitters and two independent airborne receiver instruments: induction coil magnetometers and SQUID sensors. Due to the limited investigation depth of the HEM method, local-scale electrical resistivity tomography (ERT) and long-offset transient electromagnetic (LOTEM) measurements were carried out on a reference profile, enabling the validation of inversion results at greater depths. The comparison of all inversion results provided a consistent overall resistivity distribution. It further confirmed that both semi-airborne receiver instruments achieve the bandwidth and sensitivity required for the investigation of the resistivity structure down to 1 km depth and therewith the detection of deeply seated earth resources. A 3D geological model, lithological and geophysical borehole logs as well as petrophysical investigations were integrated to interpret of the geophysical results. Distinct highly-conductive anomalies with resistivities of less than 10 Om were identified as alum shales over all scales. Apart from that, the petrophysical investigations exhibited that correlating geophysical and geological information using only one single parameter, such as the electrical resistivity, is hardly possible. Therefore, we developed a first approach based on clustering methods and self-organizing maps (SOMs) that allowed us to assign geological units at the surface to a given combination of geophysical and petrophysical parameters, obtained on different scales. © 2020 The Authors
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    Thermochemistry of the glass melting process - Energy requirement in melting soda-lime-silica glasses from cullet-containing batches
    (Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 1996) Madivate, Carvalho; Müller, Franz; Wilsmann, Wolfgang
    The theoretical energy requirement in meldng flat and Container glasses of the soda-lime-silica type from corresponding batches was directly measured at temperatures from 1370 to 1700 Κ using the drop-mixing method. In addition, the energy to be expended in headng the aforemendoned glasses, as well as calumite and ecomelt, from ambient temperature into the ränge from 1080 to 1700 Κ was determined using transposed-temperature drop calorimetry. Guided by the results, thermochemical methods proposed in the literature for the estimadon of the theoretical energy demand are critically assessed. Furthermore, the measured data are combined with information taken from thermochemical tables to derive the enthalpy effects contributing to the total enthalpy change associated with the conversion of the considered glass batches into the corresponding glass melts. On the basis of the information obtained, the ways in which the theoretical energy demand could be reduced are discussed. The influence of additions of cullet and other raw materials, such as calumite and spodumene, on the theoretical energy requirement is investigated, and the energy saving through additions of these materials is estimated.