scholarly journals Use of Local X-Ray Computerized Tomography for High-Resolution, Region-of-Interest Inspection of Large Ceramic Components for Engines

1993 ◽  
Author(s):  
E. A. Sivers ◽  
D. A. Holloway ◽  
W. A. Ellingson
Keyword(s):  
High Resolution ◽  
Computerized Tomography ◽  
Three Dimensional ◽  
Region Of Interest ◽  
Turbine Rotor ◽  
System Capacity ◽  
High Resolution Data ◽  
X Ray ◽  
Ceramic Components ◽  
Critical Regions

Reliability continues to be an issue in the development of ceramic components for high-temperature, high-wear applications in advanced engine designs. Recently, high-resolution, three-dimensional, X-ray computerized tomography (XRCT) has been shown to be invaluable for inspecting relatively small components. However, the time and system capacity required to collect complete high-resolution data for large ceramic objects is often prohibitive. When only the critical regions of a large component need be inspected with high resolution, region-of-interest XRCT is a viable alternative. By using local XRCT methods on data taken through only the critical area, it is possible to reconstruct flat, “edge-enhanced” images in which density differences are clearly delineated. We present XRCT results from local scans of critical regions in a large, pressure-slip-cast, Si3N4 turbine rotor and two Si3N4 test phantoms. We also illustrate how the method can be extended to larger assemblies of ceramic components.

scholarly journals X-Ray Tomography Applied to NDE of Ceramics

1983 ◽  
Author(s):  
J. W. Kress ◽  
L. A. Feldkamp
Keyword(s):  
Gas Turbine ◽  
Rotor Blade ◽  
Tomographic Reconstruction ◽  
Three Dimensional ◽  
Turbine Rotor ◽  
Naval Research ◽  
X Ray ◽  
Turbine Rotor Blade ◽  
Office Of Naval Research ◽  
Ceramic Components

An x-ray radiographic NDE system specifically suited to three-dimensional tomographic reconstruction is described. The results of two applications of the system are discussed. The first is the reconstruction of a section of a ceramic gas turbine rotor blade. This demonstrates the system’s ability to reconstruct parts with complex external shape. In the second, an assembly of ceramic components containing a 50 μm gap is examined. The 50 μm gap is detected. This work was supported in part by the Office of Naval Research under contract N00014-78-C-0714.

Three-dimensional crystallization of membrane proteins

1988 ◽  
Vol 21 (4) ◽  
pp. 429-477 ◽  
Author(s):  
W. Kühlbrandt
Keyword(s):  
High Resolution ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Protein Complexes ◽  
Three Dimensional ◽  
Biological Macromolecules ◽  
X Ray ◽  
X Ray Crystallography ◽  
Membrane Protein Complexes ◽  
Essential Prerequisite

As recently as 10 years ago, the prospect of solving the structure of any membrane protein by X-ray crystallography seemed remote. Since then, the threedimensional (3-D) structures of two membrane protein complexes, the bacterial photosynthetic reaction centres of Rhodopseudomonas viridis (Deisenhofer et al. 1984, 1985) and of Rhodobacter sphaeroides (Allen et al. 1986, 1987 a, 6; Chang et al. 1986) have been determined at high resolution. This astonishing progress would not have been possible without the pioneering work of Michel and Garavito who first succeeded in growing 3-D crystals of the membrane proteins bacteriorhodopsin (Michel & Oesterhelt, 1980) and matrix porin (Garavito & Rosenbusch, 1980). X-ray crystallography is still the only routine method for determining the 3-D structures of biological macromolecules at high resolution and well-ordered 3-D crystals of sufficient size are the essential prerequisite.

Three-dimensional analysis of plant structure using high-resolution X-ray computed tomography

2003 ◽  
Vol 8 (1) ◽  
pp. 2-6 ◽  
Author(s):  
Wolfgang H Stuppy ◽  
Jessica A Maisano ◽  
Matthew W Colbert ◽  
Paula J Rudall ◽  
Timothy B Rowe
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Dimensional Analysis ◽  
Three Dimensional ◽  
Plant Structure ◽  
X Ray ◽  
X Ray Computed

Three dimensional characterization of laser ablation craters using high resolution X-ray computed tomography

2018 ◽  
Vol 139 ◽  
pp. 75-82 ◽  
Author(s):  
A.H. Galmed ◽  
A. du Plessis ◽  
S.G. le Roux ◽  
E. Hartnick ◽  
H. Von Bergmann ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Laser Ablation ◽  
High Resolution ◽  
Three Dimensional ◽  
X Ray ◽  
X Ray Computed

Three Dimensional X-Ray Computed Tomography in Materials Science

MRS Bulletin ◽  
1988 ◽  
Vol 13 (1) ◽  
pp. 13-18 ◽  
Author(s):  
J.H. Kinney ◽  
Q.C. Johnson ◽  
U. Bonse ◽  
M.C. Nichols ◽  
R.A. Saroyan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Sample Preparation ◽  
Visible Light ◽  
Three Dimensional ◽  
Materials Characterization ◽  
Imaging Technology ◽  
X Ray ◽  
X Ray Imaging ◽  
Visible Light Imaging

Imaging is the cornerstone of materials characterization. Until the middle of the present century, visible light imaging provided much of the information about materials. Though visible light imaging still plays an extremely important role in characterization, relatively low spatial resolution and lack of chemical sensitivity and specificity limit its usefulness.The discovery of x-rays and electrons led to a major advance in imaging technology. X-ray diffraction and electron microscopy allowed us to characterize the atomic structure of materials. Many materials vital to our high technology economy and defense owe their existence to the understanding of materials structure brought about with these high-resolution methods.Electron microscopy is an essential tool for materials characterization. Unfortunately, electron imaging is always destructive due to the sample preparation that must be done prior to imaging. Furthermore, electron microscopy only provides information about the surface of a sample. Three dimensional information, of great interest in characterizing many new materials, can be obtained only by time consuming sectioning of an object.The development of intense synchrotron light sources in addition to the improvements in solid state imaging technology is revolutionizing materials characterization. High resolution x-ray imaging is a potentially valuable tool for materials characterization. The large depth of x-ray penetration, as well as the sensitivity of absorption crosssections to atomic chemistry, allows x-ray imaging to characterize the chemistry of internal structures in macroscopic objects with little sample preparation. X-ray imaging complements other imaging modalities, such as electron microscopy, in that it can be performed nondestructively on metals and insulators alike.

Measurement Method of X-ray Focus Projection Coordinates of Three-Dimensional Micro-Computerized Tomography Scanning System

2009 ◽  
Vol 29 (5) ◽  
pp. 1275-1280
Author(s):  
杨民 Yang Min ◽  
刘静华 Liu Jinghua ◽  
李保磊 Li Baolei ◽  
吴文晋 Wu Wenjin ◽  
王钢 Wang Gang
Keyword(s):  
Computerized Tomography ◽  
Measurement Method ◽  
Three Dimensional ◽  
Scanning System ◽  
X Ray ◽  
Tomography Scanning ◽  
Focus Projection

CT Multiscan: Using Small Area Detectors to Image Large Components

1995 ◽  
Author(s):  
E. A. Sivers ◽  
W. A. Ellingson ◽  
S. A. Snyder ◽  
D. A. Holloway
Keyword(s):  
Small Area ◽  
Dynamic Range ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Large Component ◽  
X Ray ◽  
Area Detector ◽  
Longest Path ◽  
Ceramic Components ◽  
X Ray Computed

The small size and dynamic range of the best two-dimensional X-ray detectors are impediments to the use of three-dimensional X-ray computed tomography (3D-XRCT) for 100% inspection of large ceramic components. The most common industrial 3D-XRCT systems use a “rotate-only” geometry in which the X-ray source and the area detector remain stationary while the component placed between them is rotated through 360°. This configuration offers the highest inspection speed and the best utilization of X-ray dose, but requires that the component be small enough to fit within the X-ray/detector “cone.” Also, if the object is very dense, the ratio of an unattenuated X-ray signal to that through the longest path in the component may exceed the dynamic range of the detector. To some extent, both of these disadvantages can be overcome by using “Multiscan CT,” i.e., scanning small overlapping regions of a large component separately while maximizing the X-ray dose to each. The overlapping scans can then be combined seamlessly into a single scan with optimal contrast.

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