Sökning: "direct-current resistivity"

Visar resultat 1 - 5 av 14 avhandlingar innehållade orden direct-current resistivity.

  1. 1. Ground Monitoring using Resistivity Measurements in Glaciated Terrains

    Författare :Jaana Aaltonen; KTH; []
    Nyckelord :Resistivity; DIrect Current; Monitoring; Groundwater; Contaminant; Tracer Test; Geophysics;

    Sammanfattning : The most common method of monitoring and mapping groundwatercontaminants is to extract and analyse a number of groundwatersamples from wells in the investigation area. However, thereare a number of limitations with this type of point-wiseinvestigation, as it is hard to acquire an adequate picture ofa heterogeneous and anisotropic subsurface using a fewpoints. LÄS MER

  3. 2. Improvement and Assessment of Two-Dimensional Resistivity Models Derived from Radiomagnetotelluric and Direct-Current Resistivity Data

    Författare :Thomas Kalscheuer; Laust B. Pedersen; Christopher Juhlin; Roland Roberts; Heinrich Brasse; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Electromagnetic geophysics; radiomagnetotellurics; direct-current resistivity; displacement currents; dielectric effect; non-linearity; inversion; regularization; two-dimensional model; model variance; model resolution; data resolution; Geophysics; Geofysik;

    Sammanfattning : Two-dimensional (2-D) models of electrical resistivity are improved by jointly inverting radiomagnetotelluric (RMT) and direct-current resistivity (DCR) data or by allowing for displacement currents in the inversion of RMT data collected on highly resistive bedrock. Uniqueness and stability of the 2-D models are assessed with a model variance and resolution analysis that allows for the non-linearity of the inverse problem. LÄS MER

  4. 3. Advances in time-domain induced polarization monitoring with application on chlorinated solvents contamination : Towards scalable real-time geophysical monitoring

    Författare :Aristeidis Nivorlis; Teknisk geologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geoelectrical monitoring; Chlorinated solvents; geophysics; Electrical resistivity tomography ERT ; Contaminated soil; contamination remediation geophysics;

    Sammanfattning : Environmental pollution is a significant concern for scientists, practitioners, authorities and the society. Among the various pollutants, chlorinated solvents pose a considerable risk to our groundwater resources. LÄS MER

  5. 4. Optimization of time domain induced polarization data acquisition and spectral information content

    Författare :P.-I. Olsson; Teknisk geologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; induced polarization 1P ; DCIP; spectral information; Data quality; Signal Processing;

    Sammanfattning : The need for detailed subsurface information is increasing due to city expansion and infill projects as well as subsurface construction projects. One common method for acquiring this geo-information is the direct current resistivity and time domain induced polarization method (DCIP) that measures the electrical resistivity and chargeability of the subsurface. LÄS MER

  7. 5. ZrB2 Thin Films : Growth and Characterization

    Författare :Lina Tengdelius; Hans Högberg; Urban Forsberg; Gregory S. Girolami; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Zirconium diboride, ZrB2, is a ceramic material with bulk properties such as high melting point (3245 °C), high hardness (23 GPa), and low resistivity (~8 μΩcm). Thin film growth of ZrB2 using physical vapor deposition has suffered from problems with films deviating from stoichiometry and with high levels of contaminants, especially high oxygen content. LÄS MER