End-of-Injection Behavior of Diesel Sprays Measured With X-Ray Radiography

2010 ◽  
Author(s):  
Alan Kastengren ◽  
Christopher F. Powell ◽  
Zunping Liu ◽  
Seoksu Moon ◽  
Jian Gao ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Contrast Imaging ◽  
Diesel Sprays ◽  
Engine Emissions ◽  
X Ray ◽  
Spray Density ◽  
Spray Plume ◽  
Spray Distribution ◽  
Unburned Fuel ◽  
Spray Velocity

The behavior of diesel fuel sprays at the end of injection is poorly understood, yet has important implications regarding diesel engine emissions. Recent research has shown that at the end of injection, an entrainment wave is created, causing the fuel spray to rapidly entrain ambient gas. This rapid entrainment creates a dilute mixture of fuel that may be a source of unburned fuel emissions. In this study, x-ray radiography is used to examine the end-of-injection behavior of diesel sprays. X-ray radiography permits quantitative mass distribution measurements in dense sprays, providing data that cannot be obtained with optical techniques. Analysis of the spray velocity at steady-state suggests an entrainment wave speed of several hundred m/s, which is supported by the appearance of a travelling entrainment wave at low ambient density. The spray density declines most rapidly near the nozzle, behavior that matches the expected entrainment wave behavior. In several cases, the spray distribution in a cross-section across the nozzle axis becomes smoother at the end of injection. Three-dimensional reconstructions of the spray density at the end of injection show that the spray plume widens considerably, enhancing the dilution caused by the reduction in spray mass in the flowfield. Measurements of injector needle motion with x-ray phase contrast imaging show that throttling across the needle seat may cause a smearing of the ideally sharp entrainment wave.

End-of-Injection Behavior of Diesel Sprays Measured With X-Ray Radiography

2012 ◽  
Vol 134 (9) ◽  
Author(s):  
Alan Kastengren ◽  
Christopher F. Powell ◽  
F. Zak Tilocco ◽  
Zunping Liu ◽  
Seoksu Moon ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Diesel Sprays ◽  
Engine Emissions ◽  
X Ray ◽  
Fuel Flow ◽  
Spray Density ◽  
Spray Plume ◽  
Unburned Fuel ◽  
Spray Velocity ◽  
Dilute Mixture

The behavior of diesel fuel sprays at the end of injection is poorly understood, yet has important implications regarding diesel engine emissions. Recent research has shown that at the end of injection, an entrainment wave is created, causing the fuel spray to rapidly entrain ambient gas. This rapid entrainment creates a dilute mixture of fuel that may be a source of unburned fuel emissions. In this study, X-ray radiography is used to quantitatively probe the fuel mass distribution in diesel sprays at the end of injection. Analysis of the spray velocity at steady-state suggests an entrainment wave speed of several hundred m/s, which is supported by the appearance of a traveling entrainment wave at low ambient density. The spray density declines most rapidly near the nozzle, a behavior that matches the expected entrainment wave behavior. The dilution of the spray plume is most prominent in the central dense region of the spray. Three-dimensional reconstructions of the spray density at the end of injection show that the spray plume considerably widens, enhancing the dilution caused by the reduction in fuel flow.

X-ray imaging with ultra-small-angle X-ray scattering as a contrast mechanism

2004 ◽  
Vol 37 (5) ◽  
pp. 757-765 ◽  
Author(s):  
L. E. Levine ◽  
G. G. Long
Keyword(s):  
Small Angle ◽  
Imaging Technique ◽  
Three Dimensional ◽  
Sample Volume ◽  
Contrast Imaging ◽  
X Ray ◽  
X Ray Scattering ◽  
X Ray Imaging ◽  
Contrast Mechanism ◽  
Ray Scattering

A new transmission X-ray imaging technique using ultra-small-angle X-ray scattering (USAXS) as a contrast mechanism is described. USAXS imaging can sometimes provide contrast in cases where radiography and phase-contrast imaging are unsuccessful. Images produced at different scattering vectors highlight different microstructural features within the same sample volume. When used in conjunction with USAXS scans, USAXS imaging provides substantial quantitative and qualitative three-dimensional information on the sizes, shapes and spatial arrangements of the scattering objects. The imaging technique is demonstrated on metal and biological samples.

scholarly journals A feasibility study of X-ray phase-contrast mammographic tomography at the Imaging and Medical beamline of the Australian Synchrotron

2015 ◽  
Vol 22 (6) ◽  
pp. 1509-1523 ◽  
Author(s):  
Yakov I. Nesterets ◽  
Timur E. Gureyev ◽  
Sheridan C. Mayo ◽  
Andrew W. Stevenson ◽  
Darren Thompson ◽  
...  
Keyword(s):  
Phase Contrast ◽  
Three Dimensional ◽  
High Sensitivity ◽  
Contrast Imaging ◽  
Detector Resolution ◽  
X Ray ◽  
Processing Strategies ◽  
Characteristics Analysis ◽  
Tissue Characteristics ◽  
Contrast Ct

Results are presented of a recent experiment at the Imaging and Medical beamline of the Australian Synchrotron intended to contribute to the implementation of low-dose high-sensitivity three-dimensional mammographic phase-contrast imaging, initially at synchrotrons and subsequently in hospitals and medical imaging clinics. The effect of such imaging parameters as X-ray energy, source size, detector resolution, sample-to-detector distance, scanning and data processing strategies in the case of propagation-based phase-contrast computed tomography (CT) have been tested, quantified, evaluated and optimized using a plastic phantom simulating relevant breast-tissue characteristics. Analysis of the data collected using a Hamamatsu CMOS Flat Panel Sensor, with a pixel size of 100 µm, revealed the presence of propagation-based phase contrast and demonstrated significant improvement of the quality of phase-contrast CT imaging compared with conventional (absorption-based) CT, at medically acceptable radiation doses.

scholarly journals Assisted walking in Malagasy dwarf chamaeleons

2010 ◽  
Vol 6 (6) ◽  
pp. 740-743 ◽  
Author(s):  
Renaud Boistel ◽  
Anthony Herrel ◽  
Gheylen Daghfous ◽  
Paul-Antoine Libourel ◽  
Elodie Boller ◽  
...  
Keyword(s):  
Inner Ear ◽  
Phase Contrast ◽  
Three Dimensional ◽  
Phase Contrast Imaging ◽  
Contrast Imaging ◽  
X Ray ◽  
Unique Mode ◽  
Morphological Adaptations ◽  
Long Tails

Chamaeleons are well known for their unique suite of morphological adaptations. Whereas most chamaeleons are arboreal and have long tails, which are used during arboreal acrobatic manoeuvres, Malagasy dwarf chamaeleons ( Brookesia ) are small terrestrial lizards with relatively short tails. Like other chamaeleons, Brookesia have grasping feet and use these to hold on to narrow substrates. However, in contrast to other chamaeleons, Brookesia place the tail on the substrate when walking on broad substrates, thus improving stability. Using three-dimensional synchrotron X-ray phase-contrast imaging, we demonstrate a set of unique specializations in the tail associated with the use of the tail during locomotion. Additionally, our imaging demonstrates specializations of the inner ear that may allow these animals to detect small accelerations typical of their slow, terrestrial mode of locomotion. These data suggest that the evolution of a terrestrial lifestyle in Brookesia has gone hand-in-hand with the evolution of a unique mode of locomotion and a suite of morphological adaptations allowing for stable locomotion on a wide array of substrates.

scholarly journals Three-dimensional Construction of Micrometer Level in Rat Stomach by Synchrotron RadiationThree-dimensional Construction of Micrometer Level in Rat Stomach by Synchrotron Radiation

2020 ◽  
Author(s):  
Qiang Tao ◽  
Chen-Chen Gao ◽  
Xue-Hong Tong ◽  
Shizhen Yuan ◽  
Tian-tian Wang ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Phase Contrast ◽  
Three Dimensional ◽  
Image Resolution ◽  
Phase Contrast Imaging ◽  
Imaging Method ◽  
Rat Stomach ◽  
Contrast Imaging ◽  
X Ray ◽  
3 Dimensional

Abstract Objectives This article shows an imaging method of the stomach that does not use imaging agents. X-ray phase-contrast images of different stages of gastric development were taken using X-ray in-line phase-contrast imaging (XILPCI). The aim of the study was to demonstrate that XILPCI is a micron imaging method for gastric structures. Methods The stomachs of 4-, 6- and 12-week-old rats were removed and cleaned. XILPCI has 1000 times greater soft tissue contrast than that of X-ray traditional absorption radiography. The projection images of the rats’ stomachs were recorded by an XILPCI charge coupled device (CCD) at 9 μm image resolution. Results The X-ray in-line phase-contrast images of the different stages of rat gastric specimens clearly showed the gastric architectures and the details of the gastroduodenal region. 3-dimensional stomach anatomical structure images were reconstruction. Conclusion The reconstructed gastric 3D images can clearly display the internal structure of the stomach. XILPCI may be a useful method for medical research in the future. Keywords: Synchrotron radiation phase-contrast imaging, 3-dimensional gastric structure images

High-Resolution Radiography for Detecting and Measuring Micron-Scale Features

2004 ◽  
Author(s):  
Daniel H. Morse ◽  
Arlyn J. Antolak ◽  
Bernice E. Mills
Keyword(s):  
Computed Tomography ◽  
Composite Materials ◽  
Phase Contrast ◽  
Three Dimensional ◽  
Conventional Radiography ◽  
Small Scale ◽  
Micro Computed Tomography ◽  
Contrast Imaging ◽  
X Ray ◽  
Projection Radiography

X-ray radiography has long been recognized as a valuable tool for detecting internal features and flaws. Recent developments in microfabrication and composite materials have extended inspection requirements to the resolution limits of conventional radiography. Our work has been directed toward pushing both detection and measurement capabilities to a smaller scale. Until recently, we have used conventional contact radiography, optimized to resolve small features. With the recent purchase of a nano-focus (sub-micron) x-ray source, we are now investigating projection radiography, phase contrast imaging and micro-computed tomography (μ-CT). Projection radiography produces a magnified image that is limited in spatial resolution mainly by the source size, not by film grain size or detector pixel size. Under certain conditions phase contrast can increase the ability to resolve small features such as cracks, especially in materials with low absorption contrast. Micro-computed tomography can provide three-dimensional measurements on a micron scale and has been shown to provide better sensitivity than simple radiographs. We have included applications of these techniques to small-scale measurements not easily made by mechanical or optical means. Examples include void detection in meso-scale nickel MEMS parts, measurement of edge profiles in thick gold lithography masks, and characterization of the distribution of phases in composite materials. Our work, so far, has been limited to film.

scholarly journals Towards tender X-rays with Zernike phase-contrast imaging of biological samples at 50 nm resolution

2014 ◽  
Vol 21 (4) ◽  
pp. 790-794 ◽  
Author(s):  
Ismo Vartiainen ◽  
Martin Warmer ◽  
Dennis Goeries ◽  
Eva Herker ◽  
Rudolph Reimer ◽  
...  
Keyword(s):  
Phase Contrast ◽  
Three Dimensional ◽  
Phase Contrast Imaging ◽  
X Rays ◽  
Contrast Imaging ◽  
Full Field ◽  
X Ray ◽  
Lipid Droplet Formation ◽  
Contrast Microscope ◽  
Science Application

X-ray microscopy is a commonly used method especially in material science application, where the large penetration depth of X-rays is necessary for three-dimensional structural studies of thick specimens with high-Zelements. In this paper it is shown that full-field X-ray microscopy at 6.2 keV can be utilized for imaging of biological specimens with high resolution. A full-field Zernike phase-contrast microscope based on diffractive optics is used to study lipid droplet formation in hepatoma cells. It is shown that the contrast of the images is comparable with that of electron microscopy, and even better contrast at tender X-ray energies between 2.5 keV and 4 keV is expected.

scholarly journals Micro Soft Tissues Visualization Based on X-Ray Phase-Contrast Imaging

2011 ◽  
Vol 5 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Lu Zhang ◽  
Shuqian Luo
Keyword(s):  
Phase Contrast ◽  
Soft Tissues ◽  
Early Stage ◽  
Blood Clot ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Phase Contrast Imaging ◽  
Contrast Imaging ◽  
X Ray ◽  
Non Invasive

The current imaging methods have a limited ability to visualize microstructures of biological soft tissues. Small lesions cannot be detected at the early stage of the disease. Phase contrast imaging (PCI) is a novel non-invasive imaging technique that can provide high contrast images of soft tissues by the use of X-ray phase shift. It is a new choice in terms of non-invasively revealing soft tissue details. In this study, the lung and hepatic fibrosis models of mice and rats were used to investigate the ability of PCI in microstructures observation of soft tissues. Our results demonstrated that different liver fibrosis stages could be distinguished non-invasively by PCI. The three-dimensional morphology of a segment of blood vessel was constructed. Noteworthy, the blood clot inside the vessel was visualized in three dimensions which provided a precise description of vessel stenosis. Furthermore, the whole lung airways including the alveoli were obtained. We had specifically highlighted its use in the visualization and assessment of the alveoli. To our knowledge, this was the first time for non-invasive alveoli imaging using PCI. This finding may offer a new perspective on the diagnosis of respiratory disease. All the results confirmed that PCI will be a valuable tool in biological soft tissues imaging.

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