scholarly journals Evaluation of the conventional and synchrotron X-ray tomography applied to heterogeneous oil reservoir rocks

2019 ◽  
Vol 7 (3A) ◽  
Author(s):  
Guilherme José Ramos ◽  
Paula Campos De Oliveira ◽  
Rodrigo Surmas ◽  
Leandro De Paulo Ferreira ◽  
Henning Markötter ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Acquisition Time ◽  
Micro Ct ◽  
User Friendliness ◽  
Beam Hardening ◽  
Short Acquisition Time ◽  
X Ray ◽  
Reservoir Rocks ◽  
Computed Microtomography ◽  
Multiphase Fluid

Carbonate and sandstone reservoirs play an important role in oil industry as they host over 50% of the world’s hydrocarbon reserves. For an accurately assessment of porosity and pore size distribution of such complex pore-network, which affect directly the macroscopic characteristics of multiphase fluid flow, X-ray computed microtomography (micro-CT) emerges as a powerful tool. In contrast to lab-based X-ray micro-CT (XCT), synchrotron X-ray micro-CT (SXCT) images are commonly free of artefacts (i.e. beam hardening) and the unique properties of synchrotron sources enable the X-ray imaging of complex and heterogeneous materials in greater detail, with higher quality, and short acquisition time. This work reports results of cone beam computed microtomography (XCT) in comparison with synchrotron computed microtomography (SXCT) applied to very heterogeneous carbonate and sandstone reservoir rocks. We analyze the quality of the image generated in terms of detection of details and artefacts, the advantages and limitation of each technique, as well as features like contrast, sharpness, and signal-to-noise ratio (SNR). Although SXCT offers significant advantages over XCT, the latter gains in cost of operation, accessibility and user-friendliness.  

scholarly journals Simple low dose radiography allows precise lung volume assessment in mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amara Khan ◽  
Andrea Markus ◽  
Thomas Rittmann ◽  
Jonas Albers ◽  
Frauke Alves ◽  
...  
Keyword(s):  
Lung Function ◽  
Whole Body ◽  
Acquisition Time ◽  
Micro Ct ◽  
Lung Volumes ◽  
X Ray ◽  
Promising Tool ◽  
Volume Assessment ◽  
Set Up ◽  
Time Required

AbstractX-ray based lung function (XLF) as a planar method uses dramatically less X-ray dose than computed tomography (CT) but so far lacked the ability to relate its parameters to pulmonary air volume. The purpose of this study was to calibrate the functional constituents of XLF that are biomedically decipherable and directly comparable to that of micro-CT and whole-body plethysmography (WBP). Here, we developed a unique set-up for simultaneous assessment of lung function and volume using XLF, micro-CT and WBP on healthy mice. Our results reveal a strong correlation of lung volumes obtained from radiographic XLF and micro-CT and demonstrate that XLF is superior to WBP in sensitivity and precision to assess lung volumes. Importantly, XLF measurement uses only a fraction of the radiation dose and acquisition time required for CT. Therefore, the redefined XLF approach is a promising tool for preclinical longitudinal studies with a substantial potential of clinical translation.

X-RAY COMPUTED MICROTOMOGRAPHY OF RUBBER

2012 ◽  
Vol 85 (3) ◽  
pp. 387-407 ◽  
Author(s):  
Karine Le Gorju Jago
Keyword(s):  
Experimental Methods ◽  
Mechanical Deformation ◽  
Complex Structures ◽  
Micro Ct ◽  
X Ray ◽  
Computed Microtomography ◽  
X Ray Computed ◽  
Processing Steps ◽  
Ct Studies

ABSTRACT In rubber science, X-ray computed microtomography (micro CT) is becoming an increasingly used technique to characterize 3D microstructures. As a first step, experimental methods, limitations, and data analysis are described. A review of published micro CT studies for rubber is reported. Examples of our recent works are presented, including investigations on samples or complex structures, for compact or foam rubbers. Micro CT is used to describe the evolution of microstructures relative to different processing steps, to environmental interaction, and to adaptation to a mechanical deformation. New insights and better understanding of damage mechanisms due to quasistatic, creep, and fatigue solicitations are presented from in situ micro CT experiments. Perspective studies are outlined.

scholarly journals The use of X-ray computed microtomography for graptolite detection in rock based on core internal structure visualization

2017 ◽  
Vol 67 (2) ◽  
pp. 299-306 ◽  
Author(s):  
Łukasz Kaczmarek ◽  
Anna Kozłowska ◽  
Michał Maksimczuk ◽  
Tomasz Wejrzanowski
Keyword(s):  
Numerical Models ◽  
Volume Ratio ◽  
Total Sample ◽  
Sample Volume ◽  
Baltic Basin ◽  
Visible Image ◽  
X Ray ◽  
Reservoir Rocks ◽  
Computed Microtomography ◽  
X Ray Computed

Abstract This paper presents for the first time X-ray computed microtomography (μCT) analysis as a technique for Silurian graptolite detection in rocks. The samples come from the Jantar Bituminous Claystones Member of the Opalino core, Baltic Basin, northern Poland. Images were obtained with spatial resolution of 25 μm, which enabled the authors to create a 3-D visualization and to calculate the ratio of fissure and graptolite volume to the total sample volume. A set of μCT slices was used to create a 3-D reconstruction of graptolite geometry. These μCT slices were processed to obtain a clearly visible image and the volume ratio. A copper X-ray source filter was used during exposure to reduce radiograph artifacts. Visualization of graptolite tubaria (rhabdosomes) enabled Demirastrites simulans to be identified. Numerical models of graptolites reveal promising applications for paleontological research and thus for the recognition and characterization of reservoir rocks.

scholarly journals Material Decomposition in Low-Energy Micro-CT Using a Dual-Threshold Photon Counting X-Ray Detector

2021 ◽  
Vol 9 ◽  
Author(s):  
Rasmus Solem ◽  
Till Dreier ◽  
Isabel Goncalves ◽  
Martin Bech
Keyword(s):  
Decomposition Method ◽  
Photon Counting ◽  
Low Energy ◽  
Linear Attenuation Coefficient ◽  
Micro Ct ◽  
Material Decomposition ◽  
Beam Hardening ◽  
X Ray ◽  
Photon Counting Detector ◽  
Organic Tissue

Material decomposition in computed tomography is a method for differentiation and quantification of materials in a sample and it utilizes the energy dependence of the linear attenuation coefficient. In this study, a post-image reconstruction material decomposition method is constructed for a low-energy micro-CT setup using a photon counting x-ray detector. The low photon energy range (4–11 keV) allows for K-edge contrast separation of naturally occurring materials in organic tissue without the need of additional contrast agents. The decomposition method was verified using a phantom and its capability to decompose biomedical samples was evaluated with paraffin embedded human atherosclerotic plaques. Commonly, the necessary dual energy data for material decomposition is obtained by manipulating the emitted x-ray spectrum from the source. With the photon counting detector, this data was obtained by acquiring two energy window images on each side of the K-edge of one material in the sample. The samples were decomposed into three materials based on attenuation values in manually selected regions. The method shows a successful decomposition of the verification phantom and a distinct distribution of iron, calcium and paraffin in the atherosclerotic plaque samples. Though the decompositions are affected by beam hardening and ring artifacts, the method shows potential for spectral evaluation of biomedical samples.

The role of multiple observations in small-molecule single-crystal service X-ray structure determination

2019 ◽  
Vol 75 (4) ◽  
pp. 657-673
Author(s):  
Alice E. Williams ◽  
Amber L. Thompson ◽  
David J. Watkin
Keyword(s):  
Single Crystal ◽  
Small Molecule ◽  
Capillary Tube ◽  
Signal To Noise Ratio ◽  
Incident Beam ◽  
Poor Quality ◽  
Quality Data ◽  
Acquisition Time ◽  
X Ray ◽  
Multiple Observations

In order to gain a better understanding of how to improve the quality of small-molecule single-crystal X-ray diffraction data achievable in a finite time, a study was carried out to investigate the effect of varying the multiplicity, acquisition time, detector binning, maximum resolution and completeness. The results suggest that, unless there are strong arguments for a different strategy, a good routine procedure might be to optimize the conditions necessary to get the best data from single scans, and then choose a multiplicity of observations (MoO) to utilize the available time fully. Different strategies may be required if the crystal is highly absorbing, is larger than the incident beam, is enclosed in a capillary tube or is unusual in some other way. The signal-to-noise ratio should be used with care, as collecting data for longer or at higher multiplicity appears to give a systematic underestimate of the intensity uncertainties. Further, the results demonstrate that including poor-quality data in a refinement may degrade the result and, in the general case, the accidental omission of reflections has a very small impact on the refinement as long as they are omitted at random. Systematic omission of reflections needs a convincing procedural justification.

scholarly journals Reusability of P3 facial filter in pandemic emergency: a 3D Analysis of a filter microstructure with X-Ray micro-tomography images after dry heat and UV sterilization procedures.

2020 ◽  
Author(s):  
Luca Borro ◽  
Massimiliano Raponi ◽  
Andrea Del Fattore ◽  
Franco Zanini ◽  
Francesca Di Lillo ◽  
...  
Keyword(s):  
3D Analysis ◽  
Micro Ct ◽  
Fiber Network ◽  
X Ray ◽  
Dry Heat ◽  
Maximum Thickness ◽  
Before And After ◽  
Computed Microtomography ◽  
Micro Tomography ◽  
Porosity Analysis

Abstract Objective: We sought to evaluate the effects of heating and UltraViolet (UV) sterilization on level 3 protection microstructure (P3) used on disposable filtering facepieces.Intervention: P3 facial filter has been exposed to dry heat and UV sterilization procedures.Methods: P3 facial filter samples underwent standardized sterilisation processes based on dry heat and UV irradiation techniques. We analysed key parameters of internal microstructure, such as fibres thickness and porosity, before and after sterilization using 3D data obtained with a synchrotron radiation based X-ray computed microtomography (Micro-CT). The analyzed filter has two inner layers that we called "finer" and "coarser" layers. The "finer" layer consists of a dense fibers network while the "coarser" layer has a less compact fiber network. Results: Analysis on 3D images showed no statistically significant differences between P3 Filter of Controls and dry heat/UV sterilized samples. In particular, averages fibres thickness in the finer layer of Controls, 60° dry heated and UV irradiated samples group was almost identical for each group. Average fibres thickness for coarser layer of Controls, 60° dry heated and UV irradiated samples group was very similar measuring 19.33 µm (±0.47), 18.33 µm (±0.47) and 18.66 µm (±0.47), respectively. Of note, there was no substantial difference in fibres maximum thickness in the finer layers and coarser layers. For Controls group samples maximum thickness was on average of 11.43 µm (±1.24) in the finer layer and 59.33 µm (±6.79) in the coarser layer. Similarly, 60° dry heated group samples were thickened 12.2 µm (±0.21) in the finer layer and 57.33 µm (±1.24) in the coarser layer, while UV irradiated samples group the mean max thickness is 12.23 µm (±0.90) in the finer layer and 58.00 µm (±6.68) in the coarser layer.Theoretical porosity analysis resulted of 74% and 88%, for finer and coarser layer, respectively. Theoretical porosity of finer layers tend to decrease on dry heat and UV irradiated samples when compared with the respective controls samples.Conclusions: Dry heat and UV sterilization processes do not substantially alter morphometry of the internal microstructure of the P3 filter samples studied with Micro-CT. The current study suggests that safe P3 filter facepiece reusability is theoretically feasible and should be further investigated.

scholarly journals Feasibility of Low-Dose 68Ga-DOTATATE With Short Acquisition Time Using Total-Body PET/CT in Patients With Neuroendocrine Tumor

2021 ◽  
Author(s):  
Jie Xiao ◽  
Haojun Yu ◽  
Hongyan Yin ◽  
Guobin Liu ◽  
Yan Hu ◽  
...  
Keyword(s):  
Image Quality ◽  
Dose Regimen ◽  
Low Dose ◽  
Signal To Noise Ratio ◽  
Subjective Evaluation ◽  
Blood Pool ◽  
Acquisition Time ◽  
Short Acquisition Time ◽  
Pet Ct ◽  
Total Body

Abstract Purpose To explore the feasibility of a low dose regimen with short acquisition time of 68Ga-DOTATATE total-body PET/CT without compromising image quality of patients with NETs. Methods Fifty-seven consecutive NETs patients who underwent 68Ga-DOTATATE total-body PET/CT, with a low dose regimen (0.8-1.2 MBq/kg) of 68Ga-DOTATATE and acquisition time of 10 min prior to any treatment, were enrolled in the present study. The PET data were split into 1 min, 2 min, 3 min, 4 min, 5 min, 8 min and 10 min reconstruction groups, referenced as R1, R2, R3, R4, R5, R8 and R10. The subjective evaluation of image quality was scored in 5-point Likert scale based on three aspects: the overall impression of the image quality, the image noise, the lesion detectability. The objective image quality was assessed by the signal-to-noise ratio of liver (SNRL), the coefficient of variation (CV), the SUVmax, SUVmean, SD of liver, mediastinal blood pool and lesion, the tumor-liver ratio (TLR), the tumor-mediastinal blood pool-ratio (TMR) of lesion. Results The sufficient subjective image quality with a score of 3.44±0.53 could be obtained at 3 min acquisition duration, with a kappa value of 0.90. In quantitative analysis, the value of SNRL is over 10 in all reconstruction groups. As the acquisition time increases, SNRL was increased and CV was decreased within 3 min, while SNRL and CV showed no significant different between R4-R10. There was no significant different in TMR and TLR of lesion between R1-R10 (all p < 0.05). Referenced as PET images of R10, 90 SSTR-positive lesions are identified, and all those lesions are found in the R1-R10 groups (100%).Conclusion The low-dose (0.8-1.2 MBq/kg) 68Ga-DOTATATE total-body PET/CT not only shortens acquisition time, but maintains a sufficient image quality for the NETs patients.

Some Quantification Problems in Parallel EELS Images

1990 ◽  
Vol 48 (2) ◽  
pp. 36-37
Author(s):  
G. Botton ◽  
G. L’Espérance ◽  
M.D. Ball ◽  
C.E. Gallerneault
Keyword(s):  
Electron Microscope ◽  
Imaging System ◽  
Signal To Noise Ratio ◽  
Scanning Transmission Electron Microscope ◽  
Acquisition Time ◽  
Thickness Variation ◽  
Transmission Electron ◽  
Distribution Of Elements ◽  
Scanning Transmission ◽  
Present Distribution

The recently developed parallel electron energy loss spectrometers (PEELS) have led to a significant reduction in spectrum acquisition time making EELS more useful in many applications in material science. Dwell times as short as 50 msec per spectrum with a PEELS coupled to a scanning transmission electron microscope (STEM), can make quantitative EEL images accessible. These images would present distribution of elements with the high spatial resolution inherent to EELS. The aim of this paper is to briefly investigate the effect of acquisition time per pixel on the signal to noise ratio (SNR), the effect of thickness variation and crystallography and finally the energy stability of spectra when acquired in the scanning mode during long periods of time.The configuration of the imaging system is the following: a Gatan PEELS is coupled to a CM30 (TEM/STEM) electron microscope, the control of the spectrometer and microscope is performed through a LINK AN10-85S MCA which is interfaced to a IBM RT 125 (running under AIX) via a DR11W line.

Macroprobe Mode for the Study of Segregation in Steels

1990 ◽  
Vol 48 (2) ◽  
pp. 260-261
Author(s):  
Auclair Gilles ◽  
Benoit Danièle
Keyword(s):  
Mechanical Properties ◽  
Spatial Distribution ◽  
High Performance ◽  
Volume Fraction ◽  
Sheet Steel ◽  
Acquisition Time ◽  
Chemical Information ◽  
X Ray ◽  
Accurate Quantitative Analysis ◽  
Optical Micrographs

During these last 10 years, high performance correction procedures have been developed for classical EPMA, and it is nowadays possible to obtain accurate quantitative analysis even for soft X-ray radiations. It is also possible to perform EPMA by adapting this accurate quantitative procedures to unusual applications such as the measurement of the segregation on wide areas in as-cast and sheet steel products.The main objection for analysis of segregation in steel by means of a line-scan mode is that it requires a very heavy sampling plan to make sure that the most significant points are analyzed. Moreover only local chemical information is obtained whereas mechanical properties are also dependant on the volume fraction and the spatial distribution of highly segregated zones. For these reasons we have chosen to systematically acquire X-ray calibrated mappings which give pictures similar to optical micrographs. Although mapping requires lengthy acquisition time there is a corresponding increase in the information given by image anlysis.

Information capacity and bandwidth limitations in the SEM

1989 ◽  
Vol 47 ◽  
pp. 84-85
Author(s):  
D. C. Joy ◽  
R. D. Bunn
Keyword(s):  
Signal To Noise Ratio ◽  
Critical Dimension ◽  
Information Capacity ◽  
Acquisition Time ◽  
Signal To Noise ◽  
Sem Image ◽  
Probe Size ◽  
Minimum Number ◽  
Noise Ratio ◽  
Signal Channel

The information available from an SEM image is limited both by the inherent signal to noise ratio that characterizes the image and as a result of the transformations that it may undergo as it is passed through the amplifying circuits of the instrument. In applications such as Critical Dimension Metrology it is necessary to be able to quantify these limitations in order to be able to assess the likely precision of any measurement made with the microscope.The information capacity of an SEM signal, defined as the minimum number of bits needed to encode the output signal, depends on the signal to noise ratio of the image - which in turn depends on the probe size and source brightness and acquisition time per pixel - and on the efficiency of the specimen in producing the signal that is being observed. A detailed analysis of the secondary electron case shows that the information capacity C (bits/pixel) of the SEM signal channel could be written as :

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