The quantitative impact of image blur on calculated object mass in X-ray radiography is explored. Radiographed object masses are initially estimated through experimental calibration and compared against their known true mass, with the deviation, or "apparent mass loss". Apparent mass loss occurs due to the effect of spatial blur on X-ray transmission images that reduces the measured mass because while the image intensity is conserved with spatial blur, the nonlinear conversion to path length is not. A synthetic model is proposed where an object's apparent mass loss is estimated through the amount of blur present within the radiograph image. The image blur is inferred through a combination of readily available image parameters related to the signal levels, object shape, and experimental extrinsics. A regularized regression model is built that correlates these blur parameters to the expected mass loss. The model is first trained on 2100 and tested on 140 synthetically created objects, and then later verified on two separate experimental setups of type 304 stainless steel objects imaged with a portable tube source at 150 kVp and type 6061 aluminum objects at 80 kVp. The proposed model allows for a simple post hoc reduction in errors of approximately 20% in object mass through X-ray radiography.

BackgroundX-ray imaging offers unique possibilities for Digital Image Correlation (DIC), opening the door for full-field deformation measurements of a test article in complex environments where optical DIC suffers severe biases or is impossible. While X-ray DIC has been performed in the past with standard DIC codes designed for optical images, the path-integrated nature of X-ray images places constraints on the experimental setup, predominantly that only a single surface of interest moves/deforms. These requirements are difficult to realize for many practical situations and limit the amount of information that can be garnered in a single test. Other X-ray based diagnostics such as Digital Volume Correlation (DVC) and Projection DVC (P-DVC) overcome these obstacles, but DVC is limited to quasi-static tests, and both DVC and P-DVC necessitate high-resolution computed tomography (CT) scan(s) and often require a potentially invasive pattern throughout the volume of the specimen.ObjectiveThis work presents a novel approach to measure time-resolved displacements and strains on multiple surfaces from a single series of 2D, path-integrated (PI) X-ray images, called PI-DIC.MethodsThe principle of optical flow or conservation of intensity-the foundation of DIC-was reframed for path-integrated images, for an exemplar setup comprised of two plates moving and deforming independently. Synthetic images were generated for rigid translations, rigid rotations, and uniform stretches, where each plate underwent a unique motion/deformation. Experimental specimens were fabricated (either an aluminum plate with tantalum features or a plastic plate with steel features) and the two specimens were independently translated.ResultsPI-DIC was successfully demonstrated with the synthetic images and validated with the experimental images. Prescribed displacements were recovered for each plate from the single set of path-integrated, deformed images. Errors were approximately 0.02 px for the synthetic images with 1.5% image noise, and 0.05 px for the experimental images.ConclusionsThese results provide the foundation for PI-DIC to measure motion and deformation of multiple, independent surfaces with subpixel accuracy from a single series of path-integrated X-ray images.

When subjected to certain harmonic oscillations, the gas bubble in a partially liquid-filled, closed, vertical cylinder will break up. Under certain conditions, some of the gas will migrate to the bottom due to Bjerknes forces. At sufficiently large amplitudes, the bubble will break up into gas bubbles at the top and bottom ends of the cylinder. High-speed imaging captured the dynamics of bubble breakup and gas migration. Several parameters were investigated: oscillation frequency, oscillation acceleration, gas volume fraction, and liquid viscosity.

A high-speed, two-color pyrometer was developed and employed to characterize the temperature of the ejecta from pyrotechnic igniters. The pyrometer used a single objective lens, beamsplitter, and two high-speed cameras to maximize the spatial and temporal resolutions. The pyrometer used the integrated intensity of under-resolved particles to maintain a large region of interest to capture more particles. The spectral response of the pyrometer was determined based on the response of each optical component and the total system was calibrated using a black body source to ensure accurate intensity ratios over the range of interest.

We present the results of an LDRD project, funded by the Nuclear Deterrence IA, to develop capabilities for quantitative assessment of pyrotechnic thermal output. The thermal battery igniter is used as an exemplar system. Experimental methodologies for thermal output evaluation are demonstrated here, which can help designers and engineers better specify pyrotechnic components , provide thermal output guideli nes for new formulations , and generate new metrics for assessing component performance and margin given a known failure condition. A heat - transfer analysis confirms that the dominant mode of energy transfer from the pyrotechnic output plume to the heat pellet is conduction via deposition of hot titanium particles. A simple lumped - parameter model of titanium particle heat transfer and a detailed multi - phase model of deposition heat transfer are discus sed. Pyrotechnic function, as defined by ?go/no - go? standoff testing of a heat pellet , is correlated with experimentally measured igniter plume temperature , titanium metal particle temperature, and energy deposition. Three high - speed thermal diagnostics were developed for this task. A three - color imaging pyrometer , acquiring 100k images per second on three color channels , is deployed for measurement of titanium particle temperatures. Complimenta ry measurements of the overall igniter plume emission (?color?) temperature were conducted using a transmission - grating spectrograph in line - imaging mode. Heat flux and energy deposition to a cold wall at the heat - pellet location were estimated using an er oding thermocouple probe, with a frequency response of ~5 kHz. Ultimate ?go/no - go? function in the igniter/heat - pellet system was correlated with quantitative thermal metrics, in particular surface energy deposition and plume color temperature. Titanium metal - particle and plume color temperature s both experience an upper bound approximated by the 32 45 - K boiling point of TiO 2 . Average metal - particle temperatures remained nearly constant for all standoff distances at T = 28 50 K, 300 K, while plume color t emperature and heat flux decay with standoff ? suggesting that heat - pellet failure results from a drop in metal - particle flux and not particle temperature. At 50% likelihood of heat - pellet failure , peak time - resolved plume color temperatures drop well below TiO 2 boiling to ~2000 - 2200 K, near the TiO 2 melting point. Estimates of peak heat flux decline from up to 1 GW/m 2 for near - field standoffs to below 320 MW/m 2 at 50% failure likelihood.

Time-resolved X-ray thermometry is an enabling technology for measuring temperature and phase change of components. However, current diagnostic methods are limited in their ability due to the invasive nature of probes or the requirement of coatings and optical access to the component. Our proposed developments overcome these challenges by utilizing X-rays to directly measure the objects temperature. Variable-Temperature X-ray Diffraction (VT-XRD) was performed over a wide range of temperatures and diffraction angles and was performed on several materials to analyze the patterns of the bulk materials for sensitivity. ?High-speed? VT-XRD was then performed for a single material over a small range of diffraction angles to see how fast the experiments could be performed, whilst still maintaining peaks sufficiently large enough for analysis.

X-ray stereo digital image correlation (DIC) measurements were performed at 10 kHz on the internal surface of a jointed structure in a shock tube at a shock Mach number of 1.42 and compared with optical stereo DIC measurements on the outer, visible surface of the structure. The shock tube environment introduces temperature and density gradients in the gas through which the structure was imaged, resulting in spatial and temporal index of refraction variations. These variations cause bias errors in optical DIC measurements due to beam-steering but have minimal influence on x-ray DIC measurements. These results demonstrate the utility of time-resolved x-ray DIC measurements in complicated environments where optical measurements suffer severe errors and/or are precluded by lack of optical access.

The feasibility of liquid temperature measurements using X-ray scattering is investigated for liquids with varying properties (water, ethanol, and n-dodecane) on beamline 7-BM at the Advanced Photon Source at Argonne National Laboratory. The temperature is inferred through the change in the scattering pattern from the liquid as a function of temperature using partial least squares regression. An accuracy of ∼98% or higher was achieved enabling measurements for a wide range of applications.

Carbon emission reduction targets are becoming a common goal for larger corporations and regulations associated with carbon emissions are in place in several municipalities across the United States. Calibrated energy modelling paired with large scale parametric analyses can provide insight into the most cost-effective approach to reducing carbon emissions from commercial buildings. This paper provides a standardized approach to calibrated energy modelling for this application using a case study of a large commercial office building in New York City.

Liquid thermometry during primary and secondary breakup of liquid sprays is challenging due to the presence of highly dynamic, optically complex flow features. This work evaluates the use of x-ray scattering from a focused, monochromatic beam of the Advanced Photon Source at Argonne National Laboratory for the measurement of liquid temperatures within the mixing zone of an impinging jet spray. The measured scattering profiles are converted to temperature through a previously developed two-component partial least squares (PLS) regression model. Transmitive mixing during jet merging is inferred through spatial mapping of temperatures within the impingement region. The technique exhibits uncertainties of ±2K in temperature and 2% in capturing the correct scattering profile, showing its potential utility for probing liquid temperature distributions in multiphase flows.