GLORIA

GEOMAR Library Ocean Research Information Access

X

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Online Resource
    Online Resource
    NDTFlix: Collaborative Remote Analysis of X-ray Computed Tomography Datasets
    NDT.net GmbH & Co. KG ; 2023
    In:  e-Journal of Nondestructive Testing Vol. 28, No. 3 ( 2023-03)
    Details
    In: e-Journal of Nondestructive Testing, NDT.net GmbH & Co. KG, Vol. 28, No. 3 ( 2023-03)
    Abstract: When analysing data collected from non-destructive testing, several areas of expertise are required, such as on imaging modalities, data analysis and visualisation, or the domain background in terms of the inspected material. Typically, this requires a team of experts, who are not necessarily situated at the same working place. We therefore propose a system supporting collaborative remote analysis facilitating easy access to a common workspace. The system supports a collaborative analysis of datasets by connecting interactions in a lightweight web-based viewer with those in an advanced analysis software package on a desktop PC. Our system supports both co-located and distributed collaboration on large complex datasets and allows for a simple spontaneous cross-device access. This allows a wide range of devices and immersive systems to be supported regardless of their capabilities. Viewpoints and annotations can be shared as visual cues for the analysis of collaborators. The proposed system will be presented using a case study of analysing an adaptive manufactured aeronautics component. The preliminary findings showed positive feedback of the experts regarding the creation of a flexible and fast collaborative analysis set-up.
    Type of Medium: Online Resource
    ISSN: 1435-4934
    URL: Article
    DOI: 10.58286/27702
    Language: Unknown
    Publisher: NDT.net GmbH & Co. KG
    Publication Date: 2023
    detail.hit.zdb_id: 2021293-8
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 2
    Online Resource
    Online Resource
    MIST – Mechanical In-situ Stage with Temperature control for X-ray computed tomography
    NDT.net GmbH & Co. KG ; 2023
    In:  e-Journal of Nondestructive Testing Vol. 28, No. 3 ( 2023-03)
    Details
    In: e-Journal of Nondestructive Testing, NDT.net GmbH & Co. KG, Vol. 28, No. 3 ( 2023-03)
    Abstract: X-ray Computed Tomography (CT) in combination with a tensile/compression stage can deliver great insights in the damage mechanisms of a material. As the material properties change at low and high temperatures, materials may perform differently as they do at room temperature. In this paper, a novel Mechanical In-situ Stage with Temperature control (MIST) for the usage in laboratory CT devices for high resolution - (3 μm)³ - acquisitions is presented. Since the specimen temperature is controlled by air flow, the MIST stage is suitable for testing polymers and allows cooling and heating in one test cycle (-10 °C to +100 °C). The MIST stage is a modification of the CT500 DEBEN tensile/compression stage. It enables mechanical tests that combine the application of force and temperature on a sample at the same time. A technical description of the developed stage is presented. Furthermore, its advantages compared to existing devices are explored and application fields of the MIST are shown.
    Type of Medium: Online Resource
    ISSN: 1435-4934
    URL: Article
    DOI: 10.58286/27762
    Language: Unknown
    Publisher: NDT.net GmbH & Co. KG
    Publication Date: 2023
    detail.hit.zdb_id: 2021293-8
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 3
    Online Resource
    Online Resource
    Porosity determination in additively manufactured Ti parts using X-ray tomography
    NDT.net GmbH & Co. KG ; 2019
    In:  e-Journal of Nondestructive Testing Vol. 24, No. 3 ( 2019-03)
    Details
    In: e-Journal of Nondestructive Testing, NDT.net GmbH & Co. KG, Vol. 24, No. 3 ( 2019-03)
    Abstract: Ti6Al4V is a suitable titanium alloy for all kinds of medical implants and prostheses because of its high durability and biocompatibility. Furthermore, components of high complexity can be produced via additive manufacturing which allows for more flexibility and easy prototyping of patient specific implants. However, this flexibility implies the risk of internal defects resulting from the manufacturing process. The nondestructive investigation of critical components is therefore crucial to avoid premature failure. X-ray micro-computed tomography (XCT) is a method that can resolve internal structures three dimensionally in a non-destructive way. Nevertheless, the probability to detect defects is limited by the achievable resolution and image quality of a scan. In this contribution, we performed a systematic study to determine the pore size distribution in additively manufactured Ti6Al4V parts using XCT. We focused on the influence of scanning parameters such as voxel size, tube voltage and current on the image quality that determines the outcome of the porosity analysis. Image quality was assessed via contrast to noise ratio (CNR) and slanted-edge modulation transfer function (MTF) according to ISO 12233. Furthermore, we optimized the beam hardening correction for the scans and investigated influences of different image denoising algorithms. Results showed that tube voltage and current greatly influence the CNR of the data set while the MTF is, within limits, almost constant as long as the electron beam focus is optimized. With higher physical resolution, smaller defects can be detected, which leads to porosity values of 0.36, 1.35 and 2.54% at 10, 5 and 2.5 μm resolution respectively. Image post-processing can further influence porosity outcome because of the segmentation of noise induced particles. Different image denoising algorithms therefore can heavily reduce porosity values depending on spatial resolution.
    Type of Medium: Online Resource
    ISSN: 1435-4934
    URL: Article
    DOI: 10.58286/23707
    Language: Unknown
    Publisher: NDT.net GmbH & Co. KG
    Publication Date: 2019
    detail.hit.zdb_id: 2021293-8
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 4
    Online Resource
    Online Resource
    Investigation of the eye formation in semi-hard cheese by using X-ray Computed Tomography
    NDT.net GmbH & Co. KG ; 2020
    In:  e-Journal of Nondestructive Testing Vol. 25, No. 2 ( 2020-02)
    Details
    In: e-Journal of Nondestructive Testing, NDT.net GmbH & Co. KG, Vol. 25, No. 2 ( 2020-02)
    Abstract: The eye formation in semi-hard cheese was investigated by using X-ray Computed Tomography (XCT). In order to set the optimal scan settings, a study of parameters was undertaken. Therefore, five different scan parameter combinations and two beam hardening correction (BHC) methods were tested. An Iterative Artifact Reduction (IAR) was compared to a correction approach that is based on a collection of predefined BHC curves. VG Studio MAX and Modular Algorithms for Volume Images (MAVI) were used to determine the overall volume of the eyes, as well as the number, size, distribution and the shape factor. As a result, the cheese sample contained 749 eyes and the overall volume of the eyes was 440.84 cm3. The sphericity of the measured eyes was 0.81 with a standard deviation of 0.178. Therefore, XCT and different imaging software tools allow an exact characterization of the inner structures of cheese.
    Type of Medium: Online Resource
    ISSN: 1435-4934
    URL: Article
    DOI: 10.58286/25110
    Language: Unknown
    Publisher: NDT.net GmbH & Co. KG
    Publication Date: 2020
    detail.hit.zdb_id: 2021293-8
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 5
    Online Resource
    Online Resource
    Multiscale In-situ Investigations of the Formation of Delamination in CFRP by Means of X-Ray Micro-Computed Tomography
    NDT.net GmbH & Co. KG ; 2022
    In:  e-Journal of Nondestructive Testing Vol. 27, No. 3 ( 2022-03)
    Details
    In: e-Journal of Nondestructive Testing, NDT.net GmbH & Co. KG, Vol. 27, No. 3 ( 2022-03)
    Abstract: Due to their potential of decreasing weight and emission, the importance of lightweight designs with carbon fibre reinforced polymers (CFRP) in the aeronautic and automotive industry is increasing constantly. However, the formation of cracks and delaminations is one of the most prominent failure mechanisms during mechanical loading of CFRP, significantly influencing the material’s behaviour. The effects range from no effect on the structure up to complete failure of the part. In order to assess the severity of the effects, a profound knowledge of the origin of delamination initiation, its evolution and dimension of delaminations is indispensable. To display the inner structures of the specimen, X-ray computed tomography (XCT) leads to three-dimensional images of the specimen under investigation. In a multiscale XCT approach, beginning with a lower resolution, a visualization of the position and, to a lesser extent, the dimension of the delamination can be obtained over the entire volume of the specimen. A detailed visualization of the initiation and propagation of delamination at stepwise increased loadings of the specimen is obtained with higher resolution measurements. With the aid of a simple wooden in situ loading setup, the whole process of delamination initiation and growth over a certain displacement can be monitored. These two approaches in combination with certain loading stages allows a detailed description of the performance of the specimen under load.
    Type of Medium: Online Resource
    ISSN: 1435-4934
    URL: Article
    DOI: 10.58286/26626
    Language: Unknown
    Publisher: NDT.net GmbH & Co. KG
    Publication Date: 2022
    detail.hit.zdb_id: 2021293-8
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 6
    Online Resource
    Online Resource
    Micro-computed tomography for non-destructive testing of ceramic knee implants
    NDT.net GmbH & Co. KG ; 2020
    In:  e-Journal of Nondestructive Testing Vol. 25, No. 2 ( 2020-02)
    Details
    In: e-Journal of Nondestructive Testing, NDT.net GmbH & Co. KG, Vol. 25, No. 2 ( 2020-02)
    Abstract: Introduction: There are many reasons for the failure of a total knee endoprosthesis. The most common are infection, loosening, instability, pain and abrasion of the polyethylene. It is therefore necessary to further develop the current models. This study examines a new completely metal-free ceramic total knee endoprosthesis. There are several reports on the clinical results and biomechanical testings. Non-destructive analysis by computed tomography (CT) is a new tool for analysis of a ceramic knee endoprosthesis. Methods: In this study, 16 samples of a ceramic total knee arthroplasty were scanned including left and right implants (sizes 3 to 6). Each sample was left in its original packaging during scanning in order to preserve its sterile state. During the scanning procedure, two samples of the same size were scanned jointly in order to minimize scanning time. The testing was exclusively non-destructive, which poses a challenge due to the high density of zirconium (6 g/cubic centimeter). We established a non-destructive test protocol especially for ceramic knee implants in which the scanning parameters were optimized and the sample orientation was determined by CT simulations. Additionally, methods for the reduction of beam hardening artifact were applied. Results: It could be shown that a correct presentation in the micro-computer tomograph is possible despite the high density of the ceramic. In the examined specimens, no internal material defects such as pores or fractures were found. A three-dimensional examination, even of objects with a high density, can be carried out flawlessly using the micro-CT. Summary: It was shown that no pores or cracks were found in the tested implants. Non-destructive testing in micro CT is a challenging method. The highly compressed material and the complex geometry of the femoral and tibial implants make measurement difficult. Sophisticated corrective tours of the scanning artifacts and a robust scanning protocol are necessary to achieve optimal results. This study provides the prerequisites for further analysis.
    Type of Medium: Online Resource
    ISSN: 1435-4934
    URL: Article
    DOI: 10.58286/25123
    Language: Unknown
    Publisher: NDT.net GmbH & Co. KG
    Publication Date: 2020
    detail.hit.zdb_id: 2021293-8
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 7
    Online Resource
    Online Resource
    The long journey to the training of a deep neural network for segmenting pores and fibers
    NDT.net GmbH & Co. KG ; 2022
    In:  e-Journal of Nondestructive Testing Vol. 27, No. 3 ( 2022-03)
    Details
    In: e-Journal of Nondestructive Testing, NDT.net GmbH & Co. KG, Vol. 27, No. 3 ( 2022-03)
    Abstract: Even though it is a crucial step for achieving suitable results, the preprocessing of data before it is used as input to deep neural networks is often only described as a side note. This work elaborates on the required steps in this preprocessing procedure. Specifically, we provide insights into the selection of appropriate segmentation algorithms to generate reference volumes from X-ray computed tomography (XCT) scans as training data. Furthermore, this work evaluates the criteria for the selection of an appropriate deep learning network architecture, and a quantitative comparison between networks based on U-Net and V-Net.
    Type of Medium: Online Resource
    ISSN: 1435-4934
    URL: Article
    DOI: 10.58286/26610
    Language: Unknown
    Publisher: NDT.net GmbH & Co. KG
    Publication Date: 2022
    detail.hit.zdb_id: 2021293-8
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 8
    Online Resource
    Online Resource
    Wire Arc Additive Manufacturing (WAAM) and microstructural analysis of Magnesium parts
    NDT.net GmbH & Co. KG ; 2023
    In:  e-Journal of Nondestructive Testing Vol. 28, No. 3 ( 2023-03)
    Details
    In: e-Journal of Nondestructive Testing, NDT.net GmbH & Co. KG, Vol. 28, No. 3 ( 2023-03)
    Type of Medium: Online Resource
    ISSN: 1435-4934
    URL: Article
    DOI: 10.58286/27724
    Language: Unknown
    Publisher: NDT.net GmbH & Co. KG
    Publication Date: 2023
    detail.hit.zdb_id: 2021293-8
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 9
    Online Resource
    Online Resource
    Usage of 3D U-net Convolutional Neural Network for the inspection of aerospace components
    NDT.net GmbH & Co. KG ; 2023
    In:  e-Journal of Nondestructive Testing Vol. 28, No. 3 ( 2023-03)
    Details
    In: e-Journal of Nondestructive Testing, NDT.net GmbH & Co. KG, Vol. 28, No. 3 ( 2023-03)
    Abstract: This work illustrates the use of deep learning methods applied on X-ray computed tomography (XCT) datasets to segment pores and fibres in reinforced composite components from the aeronautic industry by binary semantic segmentation. We first apply data pre-processing, and then employ a modified 3D U-Net, representing a convolutional neural network. Tweaking hyper-parameters, we have reached an optimal model for our datasets. One of the models has reached 99% segmentation accuracy when testing using a Dice function. In our experiments, pores and fibres in XCT datasets of aerospace components, more specifically of glass and carbon fibre reinforced composites, were segmented and analysed. In order to compare this modified 3D U-Net architecture with segmentation methods currently used in the industry, the datasets were also input to conventional Otsu thresholding. Our results shows that modified 3D U-Net performs better than Otsu thresholding, especially on the segmentation of small pores. Modified 3D U-Net also showed reasonable prediction accuracy when testing with an optimised model which was trained with a low number of dataset both for fibre and pore segmentation.
    Type of Medium: Online Resource
    ISSN: 1435-4934
    URL: Article
    DOI: 10.58286/27728
    Language: Unknown
    Publisher: NDT.net GmbH & Co. KG
    Publication Date: 2023
    detail.hit.zdb_id: 2021293-8
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 10
    Online Resource
    Online Resource
    Comparison of preparation methods for the structural examination of meat using micro-computed tomography
    NDT.net GmbH & Co. KG ; 2022
    In:  e-Journal of Nondestructive Testing Vol. 27, No. 3 ( 2022-03)
    Details
    In: e-Journal of Nondestructive Testing, NDT.net GmbH & Co. KG, Vol. 27, No. 3 ( 2022-03)
    Abstract: In this contribution we used micro-computed tomography (micro-CT) to analyse the structural characteristics of turkey meat. In order to increase the contrast between muscle fibers and the surrounding tissue, three different preparation methods were tested. Firstly, the structure of the meat was examined in the frozen (F) state using a Deben cooling stage and in freeze-dried (FD) state. Secondly, samples were pretreated using a contrast agent (CA) (Lugol's iodine solution) to increase the contrast of muscle fibers. The shrinkage caused by the FD process was compared by quantitative analysis of the sample´s volume and the muscular structure proportion to total volume (MV/TV).
    Type of Medium: Online Resource
    ISSN: 1435-4934
    URL: Article
    DOI: 10.58286/26624
    Language: Unknown
    Publisher: NDT.net GmbH & Co. KG
    Publication Date: 2022
    detail.hit.zdb_id: 2021293-8
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...