scholarly journals X-ray micro-tomography of Carboniferous stem-Dictyoptera: new insights into early insects

2010 ◽  
Vol 6 (5) ◽  
pp. 699-702 ◽  
Author(s):  
Russell Garwood ◽  
Mark Sutton
Keyword(s):  
High Resolution ◽  
Wing Venation ◽  
X Ray ◽  
Rapid Movement ◽  
Fossil Insect ◽  
Stem Group ◽  
Mode Of Life ◽  
Micro Tomography ◽  
High Degree ◽  
Insect Fossils

Computer reconstructions of Archimylacris eggintoni , a Carboniferous stem-group dictyopteran (‘roachoid’), are presented. A siderite-hosted specimen was scanned using high-resolution X-ray microtomography (µCT), and a ‘virtual fossil’ was created with a resolution of 17.7 µm. This has revealed the morphology in great detail, including adhesive limb structures indicative of climbing and specializations for rapid movement. The antennae are filiform, and the mandibles are comparable to those of certain extant cockroaches, suggesting a similar generalist, saprophagous diet. The reconstruction reveals a high degree of specialization, and provides insights into the mode of life of these common Palaeozoic insects. Further µCT study of insect fossils has the potential to supplement wing venation with new characters, and hence improve fossil insect phylogenies.

scholarly journals Fractal Dimension Analysis of High-Resolution X-Ray Phase Contrast Micro-Tomography Images at Different Threshold Levels in a Mouse Spinal Cord

2018 ◽  
Vol 3 (4) ◽  
pp. 48 ◽  
Author(s):  
Laura Maugeri ◽  
Mauro DiNuzzo ◽  
Marta Moraschi ◽  
Charles Nicaise ◽  
Inna Bukreeva ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Fractal Dimension ◽  
High Resolution ◽  
Fractal Analysis ◽  
Phase Contrast ◽  
Threshold Level ◽  
Mouse Spinal Cord ◽  
X Ray ◽  
Threshold Levels ◽  
Micro Tomography

Fractal analysis is a powerful method for the morphological study of complex systems that is increasingly applied to biomedical images. Spatial resolution and image segmentation are crucial for the discrimination of tissue structures at the multiscale level. In this work, we have applied fractal analysis to high-resolution X-ray phase contrast micro-tomography (XrPCμT) images in both uninjured and injured tissue of a mouse spinal cord. We estimated the fractal dimension (FD) using the box-counting method on tomographic slices segmented at different threshold levels. We observed an increased FD in the ipsilateral injured hemicord compared with the contralateral uninjured tissue, which was almost independent of the chosen threshold. Moreover, we found that images exhibited the highest fractality close to the global histogram threshold level. Finally, we showed that the FD estimate largely depends on the image histogram regardless of tissue appearance. Our results demonstrate that the pre-processing of XrPCμT images is critical to fractal analysis and the estimation of FD.

Visualisation by high resolution synchrotron X-ray phase contrast micro-tomography of gas films on submerged superhydrophobic leaves

2014 ◽  
Vol 188 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Torsten Lauridsen ◽  
Kyriaki Glavina ◽  
Timothy David Colmer ◽  
Anders Winkel ◽  
Sarah Irvine ◽  
...  
Keyword(s):  
High Resolution ◽  
Phase Contrast ◽  
X Ray ◽  
Micro Tomography

Non-invasive imaging of roots with high resolution X-ray micro-tomography

2003 ◽  
Vol 255 (1) ◽  
pp. 351-359 ◽  
Author(s):  
P.J. Gregory ◽  
D. J. Hutchison ◽  
D. B. Read ◽  
P. M. Jenneson ◽  
W. B. Gilboy ◽  
...  
Keyword(s):  
High Resolution ◽  
X Ray ◽  
Non Invasive ◽  
Micro Tomography

scholarly journals Ptychographic X-ray speckle tracking with multi-layer Laue lens systems

2020 ◽  
Vol 53 (4) ◽  
pp. 927-936 ◽  
Author(s):  
Andrew J. Morgan ◽  
Kevin T. Murray ◽  
Mauro Prasciolu ◽  
Holger Fleckenstein ◽  
Oleksandr Yefanov ◽  
...  
Keyword(s):  
High Resolution ◽  
Speckle Tracking ◽  
X Rays ◽  
Chemical Sensitivity ◽  
X Ray ◽  
Laue Lens ◽  
Layer Deposition ◽  
Recent Developments ◽  
Ray Path ◽  
High Degree

The ever-increasing brightness of synchrotron radiation sources demands improved X-ray optics to utilize their capability for imaging and probing biological cells, nano-devices and functional matter on the nanometre scale with chemical sensitivity. Hard X-rays are ideal for high-resolution imaging and spectroscopic applications owing to their short wavelength, high penetrating power and chemical sensitivity. The penetrating power that makes X-rays useful for imaging also makes focusing them technologically challenging. Recent developments in layer deposition techniques have enabled the fabrication of a series of highly focusing X-ray lenses, known as wedged multi-layer Laue lenses. Improvements to the lens design and fabrication technique demand an accurate, robust, in situ and at-wavelength characterization method. To this end, a modified form of the speckle tracking wavefront metrology method has been developed. The ptychographic X-ray speckle tracking method is capable of operating with highly divergent wavefields. A useful by-product of this method is that it also provides high-resolution and aberration-free projection images of extended specimens. Three separate experiments using this method are reported, where the ray path angles have been resolved to within 4 nrad with an imaging resolution of 45 nm (full period). This method does not require a high degree of coherence, making it suitable for laboratory-based X-ray sources. Likewise, it is robust to errors in the registered sample positions, making it suitable for X-ray free-electron laser facilities, where beam-pointing fluctuations can be problematic for wavefront metrology.

Non Invasive Failure Analysis of Passive Electronic Devices in Wireless Modules Using X-ray Micro Tomography (MicroCT)

2008 ◽  
Author(s):  
Tyler Pendleton ◽  
Luke Hunter ◽  
S. H. Lau
Keyword(s):  
High Resolution ◽  
Failure Analysis ◽  
Electronic Devices ◽  
Interesting Case ◽  
X Rays ◽  
X Ray ◽  
Case Examples ◽  
Non Invasive ◽  
Novel Approach ◽  
Micro Tomography

Abstract Conventional microCTs or 3D x-ray upgrades from existing 2D x-ray systems have two major drawbacks when they are used for failure analysis of advanced packages: Insufficient resolution to image small (1 to 5 microns) materials and the lack of imaging contrast to visualize cracks, whiskers, and defects within low Z materials. This paper discusses some of the failure analysis (FA) case studies of wireless modules using a high resolution micro x-ray CT (XCT). These examples show the value of high resolution XCT as a novel approach to some common package level defects, including some interesting case examples, where failure mechanisms have been uncovered which could not have been done, using conventional means. The non-invasive FA technique for RF modules technique has been shown to dramatically improve the FA engineers' chances of identifying defects over conventional 2D x-rays and avoid the need for physical and tedious cross sectioning of these devices.

High Resolution X‐ray Micro‐Tomography of the Posterior Ampullary Nerve

2018 ◽  
Vol 32 (S1) ◽  
Author(s):  
Marc LABROUSSE ◽  
Delphine BLANCHOT ◽  
Xavier DUBERNARD ◽  
Nicla SETTEMBRE ◽  
Claude AVISSE ◽  
...  
Keyword(s):  
High Resolution ◽  
X Ray ◽  
Micro Tomography

Visualizing wood anatomy in three dimensions with high-resolution X-ray micro-tomography (μCT ) – a review –

IAWA Journal ◽  
2013 ◽  
Vol 34 (4) ◽  
pp. 408-424 ◽  
Author(s):  
Craig R. Brodersen
Keyword(s):  
High Resolution ◽  
Wood Anatomy ◽  
Data Extraction ◽  
Three Dimensional ◽  
Cell Types ◽  
Extraction Process ◽  
Three Dimensions ◽  
Wood Structures ◽  
X Ray ◽  
Micro Tomography

High-resolution X-ray micro-tomography (μCT) has emerged as one of the most promising new tools available to wood anatomists to study the three-dimensional organization of xylem networks. This non-destructive method faithfully reproduces the spatial relationships between the different cell types and allows the user to explore wood anatomy in new and innovative ways. With μCT imaging, the sample can be visualized in any plane and is not limited to a single section or exposed plane. Conventional CT software aids in the visualization of wood structures, and newly developed custom software can be used to rapidly automate the data extraction process, thereby accelerating the rate at which samples can be analyzed for research. In this review the origins of xylem reconstructions using traditional methods are discussed, as well as the current applications of μCT in plant biology and an overview of pertinent technical considerations associated with this technique. μCT imaging offers a new perspective on wood anatomy and highlights the importance of the relationships between wood structure and function.

Live small-animal X-ray lung velocimetry and lung micro-tomography at the Australian Synchrotron Imaging and Medical Beamline

2015 ◽  
Vol 22 (4) ◽  
pp. 1049-1055 ◽  
Author(s):  
Rhiannon P. Murrie ◽  
Kaye S. Morgan ◽  
Anton Maksimenko ◽  
Andreas Fouras ◽  
David M. Paganin ◽  
...  
Keyword(s):  
High Resolution ◽  
Propagation Distance ◽  
Frame Rate ◽  
X Rays ◽  
Live Animal ◽  
X Ray ◽  
Lung Motion ◽  
Animal Imaging ◽  
Micro Tomography ◽  
Live Animal Imaging

The high flux and coherence produced at long synchrotron beamlines makes them well suited to performing phase-contrast X-ray imaging of the airways and lungs of live small animals. Here, findings of the first live-animal imaging on the Imaging and Medical Beamline (IMBL) at the Australian Synchrotron are reported, demonstrating the feasibility of performing dynamic lung motion measurement and high-resolution micro-tomography. Live anaesthetized mice were imaged using 30 keV monochromatic X-rays at a range of sample-to-detector propagation distances. A frame rate of 100 frames s−1allowed lung motion to be determined using X-ray velocimetry. A separate group of humanely killed mice and rats were imaged by computed tomography at high resolution. Images were reconstructed and rendered to demonstrate the capacity for detailed, user-directed display of relevant respiratory anatomy. The ability to perform X-ray velocimetry on live mice at the IMBL was successfully demonstrated. High-quality renderings of the head and lungs visualized both large structures and fine details of the nasal and respiratory anatomy. The effect of sample-to-detector propagation distance on contrast and resolution was also investigated, demonstrating that soft tissue contrast increases, and resolution decreases, with increasing propagation distance. This new capability to perform live-animal imaging and high-resolution micro-tomography at the IMBL enhances the capability for investigation of respiratory diseases and the acceleration of treatment development in Australia.

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