3D Micro-Tomographic imaging and Quantitative Morphometry for the Nondestructive Evaluation of Porous Biomaterials

1996 ◽  
Vol 461 ◽  
Author(s):  
R. Müller ◽  
S. Matter ◽  
P. Neuenschwander ◽  
U. W. Suter ◽  
P. Rüegsegger
Keyword(s):  
Three Dimensional ◽  
Staining Technique ◽  
Bone Architecture ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Degree Of Anisotropy ◽  
Low X ◽  
Porous Biomaterials ◽  
Structural Indices ◽  
X Ray Absorption

ABSTRACTMicro-computed tomography (μCT) is a new and emerging technique for the nondestructive assessment and analysis of the three-dimensional trabecular bone architecture. The applications of μCT with respect to the analysis of bone are manyfold. Nevertheless, it also holds high promise for the microstructural measurement and analysis of porous biomaterials. For the purpose of the study, a desk-top μCT providing a nominal isotropie resolution of 14 μm was used. Since the polymeric material has a very low X-ray absorption coefficient, the scaffolds were stained prior to measurement using a commercial X-ray contrast agent. This allowed not only to acquire important microstructural features of the diree-dimensional scaffold but also to compute standard structural indices such as BV/TV, BS/BV, Tb.N, Tb.Th, Tb.Sp and the degree of anisotropy (DA) using mean intercept length measurements. The preliminary results show that different types of scaffolds can be distinguished both qualitatively (visualization) and quantitatively (morphometry) provided an adequate X-ray staining technique is used. It can be concluded that, in the future, μCT may be of considerable help in basic as well as in applied research and development.

Dislocation Vector Analysis Method of Deep Dislocation Having C-Axis Segment in Diamond

2020 ◽  
Vol 1004 ◽  
pp. 519-524 ◽  
Author(s):  
Shinichi Shikata ◽  
Naoya Akashi
Keyword(s):  
Three Dimensional ◽  
Vector Analysis ◽  
X Rays ◽  
Analysis Method ◽  
Burgers Vector ◽  
X Ray ◽  
Semiconductor Crystals ◽  
Low X ◽  
X Ray Absorption ◽  
Geometrical Relationship

X-ray topography is an effective tool to investigate dislocations in semiconductor crystals. Due to low X-ray absorption coefficients of diamond, X-rays can penetrate deep into the crystal. Thus, deep three-dimensional (3D) dislocations are projected on two-dimension (2D) film, which makes dislocation analysis particularly challenging. Dislocation vectors from the films obtained using a set of the same diffraction vectors were identified using topographical and geometrical analyses. The depth and position of the dislocations in a crystal that was projected on a film were determined using geometrical relationship. The proposed analysis method was verified by analyzing several dislocations using four <404> diffraction films. The types of dislocation were identified through Burgers vector analysis.

scholarly journals In Situ Investigation of the Early-Stage Growth of Nanoporous Alumina

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Thérèse Gorisse ◽  
Ludovic Dupré ◽  
Marc Zelsmann ◽  
Alina Vlad ◽  
Alessandro Coati ◽  
...  
Keyword(s):  
Early Stage ◽  
Grazing Incidence ◽  
Alumina Layer ◽  
Nanoporous Alumina ◽  
X Ray ◽  
X Ray Scattering ◽  
In Situ Investigation ◽  
Low X ◽  
X Ray Absorption

We report the successful use of in situ grazing incidence small-angle X-ray scattering to follow the anodization of aluminum. A dedicated electrochemical cell was designed and developed for this purpose with low X-ray absorption, with the possibility to access all azimuthal angles (360°) and to remotely control the temperature of the electrolyte. Three well-known fabrication techniques of nanoporous alumina, i.e., single, double, and pretextured, were investigated. The differences in the evolution of the scattering images are described and explained. From these measurements, we could determine at which moment the pores start growing even for very short anodization times. Furthermore, we could follow the thickness of the alumina layer as a function of the anodization time by monitoring the period of the Kiessig fringes. This work is aimed at helping to understand the different steps taking place during the anodization of aluminum at the very early stages of nanoporous alumina formation.

scholarly journals Temperature dependence of amorphous magnesium carbonate structure studied by PDF and XAFS analyses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gen-ichiro Yamamoto ◽  
Atsushi Kyono ◽  
Satoru Okada
Keyword(s):  
Temperature Dependence ◽  
Three Dimensional ◽  
Magnesium Carbonate ◽  
Range Order ◽  
Edge Structure ◽  
Medium Range Order ◽  
X Ray ◽  
Medium Range ◽  
Mineral Trapping ◽  
X Ray Absorption

AbstractMineral trapping through the precipitation of carbonate minerals is a potential approach to reduce CO2 accumulation in the atmosphere. The temperature dependence of amorphous magnesium carbonate (AMC), a precursor of crystalline magnesium carbonate hydrates, was investigated using synchrotron X-ray scattering experiments with atomic pair distribution function (PDF) and X-ray absorption fine structure analysis. PDF analysis revealed that there were no substantial structural differences among the AMC samples synthesized at 20, 60, and 80 °C. In addition, the medium-range order of all three AMC samples was very similar to that of hydromagnesite. Stirring in aqueous solution at room temperature caused the AMC sample to hydrate immediately and form a three-dimensional hydrogen-bonding network. Consequently, it crystallized with the long-range structural order of nesquehonite. The Mg K-edge X-ray absorption near-edge structure spectrum of AMC prepared at 20 °C was very similar to that of nesquehonite, implying that the electronic structure and coordination geometry of Mg atoms in AMC synthesized at 20 °C are highly similar to those in nesquehonite. Therefore, the short-range order (coordination environment) around the Mg atoms was slightly modified with temperature, but the medium-range order of AMC remained unchanged between 20 and 80 °C.

Solving the 3D structure of metal nanoparticles

2007 ◽  
Vol 222 (11/2007) ◽  
Author(s):  
Anatoly Frenkel
Keyword(s):  
Metal Nanoparticles ◽  
Short Range ◽  
Short Range Order ◽  
3D Structure ◽  
Three Dimensional ◽  
X Ray ◽  
Particle Distributions ◽  
Structure Of Metal ◽  
X Ray Absorption

We discuss methods of Extended X-ray Absorption Fine-Structure (EXAFS) analysis that provide three-dimensional structural characterization of metal nanoparticles, both mono- and bi-metallic. For the bimetallic alloys, we use short range order measurements to discriminate between random and non-random inter-particle distributions of atoms. We also discuss the application of EXAFS to heterogeneous nanoparticle systems.

X-Ray Absorption-Edge Determination of Cobalt in Complex Mixtures*

1961 ◽  
Vol 5 ◽  
pp. 379-388
Author(s):  
E.A. Hakkila ◽  
G.R. Waterbury
Keyword(s):  
Nitric Acid ◽  
Absorption Edge ◽  
Path Length ◽  
Construction Materials ◽  
X Ray ◽  
Relative Standard ◽  
Standard Deviations ◽  
Low X ◽  
X Ray Absorption

AbstractThe application of the X-ray absorption-edge technique was extended to the determination of cobalt in aqueous and alcoholic solutions containing a wide variety of impurity elements. In the procedure developed, secondary radiation from a 50% copper-nickel alloy is passed through an absorption cell filled alternately with the solvent and the sample solution. The transmitted Intensities of the Kα lines for copper and nickel are measured, and the concentration of cobalt is determined using accepted absorption principles. The K absorption edge for cobalt occurs at 1.604 A, restricting cell construction materials and solvents to those containing light elements with low X-ray absorption characteristics and also limiting the path length of the cell.Cells of 0.16- and 0.34-cm path length were used in the analysis of aqueous and alcoholic solutions, respectively. With the 0.16-cm path-length cell, relative standard deviations of 4.6 to 0.5% were obtained for cobalt concentrations ranging from 1.00 to 10.00 mg/ml for known aqueous solutions that contain various known concentrations of nitric acid. With the longer path-length cell, relative standard deviations from 1.8 to 0.46% were obtained for cobalt concentrations in the same range in known alcoholic solutions containing various known concentrations of nitric acid. The standard deviation of determining the blank is 0.043 mg of cobalt per milliliter for the 0.16-cm cell and 0.016 mg of cobalt per milliliter for the longer cell.A Norelco X-ray spectrograph with a three-position head was used in these analyses. Less than 5 min is required to convert this instrument from normal fluorescence operation to absorption-edge analysis. Approximately 15 to 20 analyses can be performed daily.

scholarly journals 3D immersive visualization of micro-computed tomography and XRD texture datasets

2019 ◽  
Vol 34 (2) ◽  
pp. 97-102
Author(s):  
M. A. Rodriguez ◽  
T. T. Amon ◽  
J. J. M. Griego ◽  
H. Brown-Shaklee ◽  
N. Green
Keyword(s):  
Computed Tomography ◽  
Texture Analysis ◽  
Mechanical Strain ◽  
Three Dimensional ◽  
Multidimensional Analysis ◽  
Micro Computed Tomography ◽  
X Ray ◽  
3D Data ◽  
Pole Figures ◽  
Ct Data

Advancements in computer technology have enabled three-dimensional (3D) reconstruction, data-stitching, and manipulation of 3D data obtained on X-ray imaging systems such as micro-computed tomography (μ-CT). Likewise, intuitive evaluation of these 3D datasets can be enhanced by recent advances in virtual reality (VR) hardware and software. Additionally, the generation, viewing, and manipulation of 3D X-ray diffraction datasets, such as pole figures employed for texture analysis, can also benefit from these advanced visualization techniques. We present newly-developed protocols for porting 3D data (as TIFF-stacks) into a Unity gaming software platform so that data may be toured, manipulated, and evaluated within a more-intuitive VR environment through the use of game-like controls and 3D headsets. We demonstrate this capability by rendering μ-CT data of a polymer dogbone test bar at various stages of in situ mechanical strain. An additional experiment is presented showing 3D XRD data collected on an aluminum test block with vias. These 3D XRD data for texture analysis (χ, ϕ, 2θ dimensions) enables the viewer to visually inspect 3D pole figures and detect the presence or absence of in-plane residual macrostrain. These two examples serve to illustrate the benefits of this new methodology for multidimensional analysis.

scholarly journals Solving the Structure and Dynamics of Metal Nanoparticles by Combining X-Ray Absorption Fine Structure Spectroscopy and Atomistic Structure Simulations

2019 ◽  
Vol 12 (1) ◽  
pp. 501-522 ◽  
Author(s):  
J. Timoshenko ◽  
Z. Duan ◽  
G. Henkelman ◽  
R.M. Crooks ◽  
A.I. Frenkel
Keyword(s):  
Fine Structure ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Structural Refinement ◽  
Particle Structure ◽  
X Ray ◽  
Structure And Dynamics ◽  
Absorption Fine ◽  
Metal Metal ◽  
X Ray Absorption

Extended X-ray absorption fine structure (EXAFS) spectroscopy is a premiere method for analysis of the structure and structural transformation of nanoparticles. Extraction of analytical information about the three-dimensional structure and dynamics of metal–metal bonds from EXAFS spectra requires special care due to their markedly non-bulk-like character. In recent decades, significant progress has been made in the first-principles modeling of structure and properties of nanoparticles. In this review, we summarize new approaches for EXAFS data analysis that incorporate particle structure modeling into the process of structural refinement.

Region-of-Interest X-Ray Tomography for the Non-Destructive Characterization of Local Fiber Orientation in Large Fiber Composite Parts

2019 ◽  
Vol 809 ◽  
pp. 587-593
Author(s):  
Simon Zabler ◽  
Katja Schladitz ◽  
Kilian Dremel ◽  
Jonas Graetz ◽  
Dascha Dobrovolskij
Keyword(s):  
Computed Tomography ◽  
Spatial Resolution ◽  
Fiber Orientation ◽  
Fiber Composite ◽  
Three Dimensional ◽  
Region Of Interest ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Anisotropic Thermal Conductivity ◽  
Local Fiber

To detect and characterize materials defects in fiber composites as well as for evaluatingthe three-dimensional local fiber orientation in the latter, X-ray micro-CT is the preferred methodof choice. When micro computed tomography is applied to inspect large components, the method isreferred to as region-of-interest computed tomography. Parts can be as large as 10 cm wide and 1 mlong, while the measurement volume of micro computed tomography is a cylinder of only 4 − 5 mmdiameter (typical wall thickness of fiber composite parts). In this report, the potentials and limits ofregion-of-interest computed tomography are discussed with regard to spatial resolution and precisionwhen evaluating defects and local fiber orientation in squeeze cast components. The micro computedtomography scanner metRIC at Fraunhofer‘s Development Center X-ray Technology EZRT deliversregion-of-interest computed tomography up to a spatial resolution of 2 μm/voxel, which is sufficientfor determining the orientation of natural or synthetic fibers, wood, carbon and glass. The mean localfiber orientation is estimated on an isotropic structuring element of approximately 0.1 mm length bymeans of volume image analysis (MAVI software package by Fraunhofer ITWM). Knowing the exactlocal fiber orientation is critical for estimating anisotropic thermal conductivity and materials strength.

Hard and soft X-ray imaging to resolve human ovarian cortical structures

2019 ◽  
Vol 26 (4) ◽  
pp. 1322-1329 ◽  
Author(s):  
Lorella Pascolo ◽  
Gabriela Sena ◽  
Alessandra Gianoncelli ◽  
Alice Cernogoraz ◽  
Geroge Kourousias ◽  
...  
Keyword(s):  
Phase Contrast ◽  
Early Stage ◽  
Ovarian Tissue ◽  
Theoretical Biology ◽  
Reproductive Technologies ◽  
Small Range ◽  
Micro Computed Tomography ◽  
Contrast Imaging ◽  
X Ray ◽  
X Ray Absorption

Laboratory and synchrotron X-ray tomography are powerful tools for non-invasive studies of biological samples at micrometric resolution. In particular, the development of phase contrast imaging is enabling the visualization of sample details with a small range of attenuation coefficients, thus allowing in-depth analyses of anatomical and histological structures. Reproductive medicine is starting to profit from these techniques, mainly applied to animal models. This study reports the first imaging of human ovarian tissue where the samples consisted of surgically obtained millimetre fragments, properly fixed, stained with osmium tetroxide and included in epoxydic resin. Samples were imaged by the use of propagation phase contrast synchrotron radiation micro-computed tomography (microCT), obtained at the SYRMEP beamline of Elettra light source (Trieste, Italy), and X-ray absorption microCT at the Theoretical Biology MicroCT Imaging Laboratory in Vienna, Austria. The reconstructed microCT images were compared with the soft X-ray absorption and phase contrast images acquired at the TwinMic beamline of Elettra in order to help with the identification of structures. The resulting images allow the regions of the cortex and medulla of the ovary to be distinguished, identifying early-stage follicles and visualizing the distribution of blood vessels. The study opens to further application of micro-resolved 3D imaging to improve the understanding of human ovary's structure and support diagnostics as well as advances in reproductive technologies.

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