scholarly journals Limb bone scaling in hopping macropods and quadrupedal artiodactyls

2018 ◽  
Vol 5 (10) ◽  
pp. 180152 ◽  
Author(s):  
Michael Doube ◽  
Alessandro A. Felder ◽  
Melissa Y. Chua ◽  
Kalyani Lodhia ◽  
Michał M. Kłosowski ◽  
...  
Keyword(s):  
High Speed ◽  
Bone Adaptation ◽  
Scaling Relations ◽  
X Ray ◽  
Limb Bones ◽  
Scaling Relationships ◽  
Low Intensity ◽  
Wide Range ◽  
Mammalian Herbivore ◽  
Highly Loaded

Bone adaptation is modulated by the timing, direction, rate and magnitude of mechanical loads. To investigate whether frequent slow, or infrequent fast, gaits could dominate bone adaptation to load, we compared scaling of the limb bones from two mammalian herbivore clades that use radically different high-speed gaits, bipedal hopping (suborder Macropodiformes; kangaroos and kin) and quadrupedal galloping (order Artiodactyla; goats, deer and kin). Forelimb and hindlimb bones were collected from 20 artiodactyl and 15 macropod species (body mass M 1.05–1536 kg) and scanned in computed tomography or X-ray microtomography. Second moment of area ( I max ) and bone length ( l ) were measured. Scaling relations ( y = ax b ) were calculated for l versus M for each bone and for I max versus M and I max versus l for every 5% of length. I max versus M scaling relationships were broadly similar between clades despite the macropod forelimb being nearly unloaded, and the hindlimb highly loaded, during bipedal hopping. I max versus l and l versus M scaling were related to locomotor and behavioural specializations. Low-intensity loads may be sufficient to maintain bone mass across a wide range of species. Occasional high-intensity gaits might not break through the load sensitivity saturation engendered by frequent low-intensity gaits.

scholarly journals Limb bone scaling in hopping macropods and quadrupedal artiodactyls

2018 ◽  
Author(s):  
Michael Doube ◽  
Alessandro A Felder ◽  
Melissa Y Chua ◽  
Kalyani Lodhia ◽  
Michał M Kłosowski ◽  
...  
Keyword(s):  
High Speed ◽  
Bone Adaptation ◽  
Scaling Relations ◽  
X Ray ◽  
Limb Bones ◽  
Scaling Relationships ◽  
Low Intensity ◽  
Wide Range ◽  
Mammalian Herbivore ◽  
Highly Loaded

AbstractBone adaptation is modulated by the timing, direction, rate, and magnitude of mechanical loads. To investigate whether frequent slow, or infrequent fast, gaits could dominate bone adaptation to load, we compared scaling of the limb bones from two mammalian herbivore clades that use radically different high-speed gaits, bipedal hopping (suborder Macropodiformes; kangaroos and kin) and quadrupedal galloping (order Artiodactyla; goats, deer and kin). Forelimb and hindlimb bones were collected from 20 artiodactyl and 15 macropod species (body mass M 1.05 – 1536 kg) and scanned in computed tomography or X- ray microtomography. Second moment of area (Imax) and bone length (l) were measured. Scaling relations (y = axb) were calculated for l vs M for each bone and for Imax vs M and Imax vs l for every 5% of length. Imax vs M scaling relationships were broadly similar between clades despite the macropod forelimb being nearly unloaded, and the hindlimb highly loaded, during bipedal hopping. Imax vs l and l vs M scaling were related to locomotor and behavioural specialisations. Low-intensity loads may be sufficient to maintain bone mass across a wide range of species. Occasional high-intensity gaits might not break through the load sensitivity saturation engendered by frequent low-intensity gaits.

scholarly journals MEASURING DISPLACEMENT AND VELOCITY OF A STRIKER USING A RADIO-INTERFEROMETER

2019 ◽  
Vol 81 (1) ◽  
pp. 118-128
Author(s):  
V. V. Balandin ◽  
V. V. Balandin ◽  
V. V. Parkhachev
Keyword(s):  
High Speed ◽  
Radio Interferometer ◽  
Experimental Investigations ◽  
X Ray ◽  
Gas Gun ◽  
Impact Interaction ◽  
Ballistic Experiment ◽  
Wide Range ◽  
Series Of Experiments ◽  
Error Of Measurement

Investigating impact interaction of solid and deformed bodies with obstacles of various physical natures requires developing experimental methodologies of registering the parameters of the interaction process. In experimental investigations of impact interaction of solids, it is common practice to measure displacement of strikers as a function of time, as well as their velocity and deceleration. To determine the displacement and velocity of a striker, a radio-interferometric methodology of registering the displacement of its rear end is proposed. In contrast with the registration methods based on high-speed filming and pulsed X-ray photography, the method using a millimeter-range radio-interferometer provides continuous high-accuracy registering of the displacement of the rear end of a striker in a wide range of displacement values. To test the effectiveness of the methodology, a series of experiments have been conducted on registering the motion of a cylindrical striker of an aluminum alloy, fired from a 20mm-dia gas gun. The displacement of the striker was also monitored using high-speed filming. The results of measuring using the two methodologies differ within the limits of the error of measurement. Based on the results of the above experiments, it has been concluded that the methodology of determining the displacement and velocity of strikers in a ballistic experiment using a mm-range radio-interferometer makes it possible to measure practically continuously large displacements (100 mm and larger) to a safe accuracy. The present methodology can be used for measuring the displacement and velocity of the rear end of a striker interacting with obstacles of various physical natures (metals, ceramics, soils, concretes, etc.).

scholarly journals 4D imaging of sub-second dynamics in pore-scale processes using real time synchrotron x-ray tomography

2016 ◽  
Author(s):  
Katherine J. Dobson ◽  
Sophia B. Coban ◽  
Sam A. McDonald ◽  
Joanna Walsh ◽  
Robert Atwood ◽  
...  
Keyword(s):  
Real Time ◽  
High Frequency ◽  
High Speed ◽  
Motion Blur ◽  
Transport Processes ◽  
Fluid Distribution ◽  
Pore Scale ◽  
X Ray ◽  
Wide Range ◽  
In Situ Experiments

Abstract. A variable volume flow cell has been integrated with state-of-the-art ultra-high speed synchrotron x-ray tomography imaging. The combination allows the first real time (sub-second) capture of dynamic pore (micron) scale fluid transport processes in 4D (3D + time). With 3D data volumes acquired at up to 20 Hz, we perform in situ experiments that capture high frequency pore-scale dynamics in 5–25 mm diameter samples with voxel (3D equivalent of a pixel) resolution of 2.5 to 3.8 µm. The data are free from motion artefacts, can be spatially registered or collected in the same orientation making them suitable for detailed quantitative analysis of the dynamic fluid distribution pathways and processes. The method presented here are capable of capturing a wide range of high frequency non equilibrium pore-scale processed including wetting, dilution, mixing and reaction phenomena, without sacrificing significant spatial resolution. As well as fast streaming (continuous acquisition) at 20 Hz, it also allows larger-scale and longer term experimental runs to be sampled intermittently at lower frequency (time-lapse imaging); benefiting from fast image acquisition rates to prevent motion blur in highly dynamic systems. This marks a major technical breakthrough for quantification of high frequency pore scale processes: processes that are critical for developing and validating more accurate multiscale flow models through spatially and temporally heterogeneous pore networks.

scholarly journals Growth and instability of the liquid rim in the crown splash regime

2014 ◽  
Vol 752 ◽  
pp. 485-496 ◽  
Author(s):  
G. Agbaglah ◽  
R. D. Deegan
Keyword(s):  
Thin Film ◽  
High Speed ◽  
Unstable Mode ◽  
Linear Stability Theory ◽  
Scaling Relations ◽  
X Ray ◽  
X Ray Imaging ◽  
Secondary Droplets ◽  
The Impact ◽  
Good Agreement

AbstractWe study the formation, growth and disintegration of jets following the impact of a drop on a thin film of the same liquid for $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}\mathit{We}<1000$ and $\mathit{Re}<2000$ using a combination of numerical simulations and linear stability theory (Agbaglah, Josserand & Zaleski, Phys. Fluids, vol. 25, 2013, 022103). Our simulations faithfully capture this phenomena and are in good agreement with experimental profiles obtained from high-speed X-ray imaging. We obtain scaling relations from our simulations and use these as inputs to our stability analysis. The resulting predictions for the most unstable wavelength are in excellent agreement with experimental data. Our calculations show that the dominant destabilizing mechanism is a competition between capillarity and inertia but that deceleration of the rim provides an additional boost to growth. We also predict over the entire parameter range of our study the number and timescale for formation of secondary droplets formed during a splash, based on the assumption that the most unstable mode sets the droplet number.

scholarly journals Improved evaluation of granular media flows using an X-ray scanning compatible cone-plate setup

2021 ◽  
Vol 249 ◽  
pp. 03020
Author(s):  
Zohreh Farmani ◽  
Jing Wang ◽  
Ralf Stannarius ◽  
Martina Bieberle ◽  
Frank Barthel ◽  
...  
Keyword(s):  
Granular Materials ◽  
High Speed ◽  
Granular Media ◽  
Flow Behavior ◽  
Three Dimensional ◽  
High Speed Imaging ◽  
Flow Measurements ◽  
Flow Rates ◽  
X Ray ◽  
Wide Range

To understand the typically heterogeneous flowing behavior of granular materials, it is important to combine flow tests with three-dimensional imaging. To probe the flow behavior of granular materials over a wide range of flow rates, it is imperative to be able to impose such flow rates in a well controlled manner while performing imaging tests that are compatible with all imposed flow rates. Achieving both flow control and bulk imaging capacity is challenging for a number of reasons. Here, we describe the design of a setup in which we are able to do imaging while imposing a constant overall shear rate on a granular material. We characterize the setup in which flow tests will be performed, which consists of a bottom-driven cone-plate or double-cone design. We show that the setup can be integrated in x-ray microtomography devices to aid particle tracking based flow measurements. The design is also compatible with typical rheometer setups. We also perform high speed imaging of a granular flow in an ultra-fast x-ray scanner, for which we provide proof-of-principle data in a simplified shear setup. The designed flow geometry is also compatible with said high speed imaging facility, where particle image velocimetry can be employed to extract quantitative flow field data.

scholarly journals Locomotory stresses in the limb bones of two small mammals: the ground squirrel and chipmunk

1983 ◽  
Vol 103 (1) ◽  
pp. 131-154 ◽  
Author(s):  
A. A. Biewener
Keyword(s):  
Safety Factor ◽  
Ground Squirrel ◽  
High Speed ◽  
Bone Geometry ◽  
Direct Consequence ◽  
Material Strength ◽  
Small Animals ◽  
Limb Bones ◽  
Wide Range ◽  
Large Animals

Peak stresses acting in limb bones should increase with increasing size if the forces acting on the bones increase in direct proportion to the animal's body weight. This is a direct consequence of the scaling of limb bone geometry over a wide range in size in mammals. In addition, recent work has shown that the material strength of bone is similar in large and small animals. If the assumptions in this analysis are correct, large animals would have a lower safety factor to failure than small animals. The purpose of this study was to measure peak stresses acting in the limb bones of small animals during locomotion and compare the results with similar measurements available for larger animals. Locomotory stresses acting in the fore and hindlimb bones of two rodents, the ground squirrel (Spermophilus tridecemlineatus) and chipmunk (Tamais striatus), were calculated using ground force recordings and measurements of limb position taken from high speed x-ray cine films. Peak (compressive) stresses calculated to act in the bones of these animals (−31 to −86 MN/m2) are similar in magnitude to those determined for much larger mammals. The more proximal bones of the fore and hindlimb, the humerus and femur, were found to develop stresses (−31 to −42 MN/m2) significantly lower than those acting in the more distal bones of each limb: the radius, ulna and tibia (−58 to −86 MN/m2). All of the long bones from both species, except their femora, were found to be loaded principally in bending. The caudal cortices of each bone developed a peak compressive stress, whereas the cranial cortices were loaded in tension. Various features of the musculo-skeletal organization and manner of locomotion of these rodents are considered to explain how animals of different size maintain a uniform safety factor to failure.

scholarly journals Quantitative analysis of dribble volumes and rates using three-dimensional reconstruction of X-ray and diffused back-illumination images of diesel sprays

2019 ◽  
Vol 21 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Vitaliy Sechenyh ◽  
Daniel J Duke ◽  
Andrew B Swantek ◽  
Katarzyna E Matusik ◽  
Alan L Kastengren ◽  
...  
Keyword(s):  
High Speed ◽  
Imaging System ◽  
Process Analysis ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Injection Pressure ◽  
X Ray ◽  
Temperature Conditions ◽  
Processing Approach ◽  
Wide Range

Post-injection fuel dribble is known to lead to incomplete atomisation and combustion due to the release of slow-moving, and often surface-bound, liquid fuel after the end of injection. This can have a negative effect on engine emissions, performance and injector durability. To better quantify this phenomenon, we developed an image-processing approach to measure the volume of ligaments produced during the end of injection. We applied our processing approach to an Engine Combustion Network ‘Spray B’ 3-hole injector, using datasets from 220 injections generated by different research groups, to decouple the effect of gas temperature and pressure on the fuel dribble process. High-speed X-ray phase-contrast images obtained at room temperature conditions (297 K) at the Advanced Photon Source at Argonne National Laboratory, together with diffused back-illumination images captured at a wide range of temperature conditions (293–900 K) by CMT Motores Térmicos were analysed and compared quantitatively. We found a good agreement between image sets obtained by Argonne National Laboratory and CMT Motores Térmicos using different imaging techniques. The maximum dribble volume within the field of view of the imaging system and the mean rate of fuel dribble were considered as characteristic parameters of the fuel dribble process. Analysis showed that the absolute mean dribble rate increases with temperature when injection pressure is higher than 1000 bar and slightly decreases at high injection pressures (>500 bar) when temperature is close to 293 K. Larger maximum volumes of the fuel dribble were observed at lower gas temperatures (∼473 K) and low gas pressures (<30 bar), with a slight dependence on injection pressure.

scholarly journals 4-D imaging of sub-second dynamics in pore-scale processes using real-time synchrotron X-ray tomography

Solid Earth ◽  
2016 ◽  
Vol 7 (4) ◽  
pp. 1059-1073 ◽  
Author(s):  
Katherine J. Dobson ◽  
Sophia B. Coban ◽  
Samuel A. McDonald ◽  
Joanna N. Walsh ◽  
Robert C. Atwood ◽  
...  
Keyword(s):  
Real Time ◽  
High Frequency ◽  
High Speed ◽  
Motion Blur ◽  
Transport Processes ◽  
Fluid Distribution ◽  
Pore Scale ◽  
X Ray ◽  
Wide Range ◽  
In Situ Experiments

Abstract. A variable volume flow cell has been integrated with state-of-the-art ultra-high-speed synchrotron X-ray tomography imaging. The combination allows the first real-time (sub-second) capture of dynamic pore (micron)-scale fluid transport processes in 4-D (3-D + time). With 3-D data volumes acquired at up to 20 Hz, we perform in situ experiments that capture high-frequency pore-scale dynamics in 5–25 mm diameter samples with voxel (3-D equivalent of a pixel) resolutions of 2.5 to 3.8 µm. The data are free from motion artefacts and can be spatially registered or collected in the same orientation, making them suitable for detailed quantitative analysis of the dynamic fluid distribution pathways and processes. The methods presented here are capable of capturing a wide range of high-frequency nonequilibrium pore-scale processes including wetting, dilution, mixing, and reaction phenomena, without sacrificing significant spatial resolution. As well as fast streaming (continuous acquisition) at 20 Hz, they also allow larger-scale and longer-term experimental runs to be sampled intermittently at lower frequency (time-lapse imaging), benefiting from fast image acquisition rates to prevent motion blur in highly dynamic systems. This marks a major technical breakthrough for quantification of high-frequency pore-scale processes: processes that are critical for developing and validating more accurate multiscale flow models through spatially and temporally heterogeneous pore networks.

scholarly journals The Quasar Continuum

2009 ◽  
Vol 5 (S267) ◽  
pp. 55-64
Author(s):  
Martin Elvis
Keyword(s):  
Continuum Emission ◽  
Spectral Energy ◽  
Scaling Relations ◽  
Physical Parameters ◽  
Spectral Energy Distributions ◽  
Energy Distributions ◽  
X Ray ◽  
Wide Range

AbstractThe powerful compact continuum emission from quasars is understood only in outline. New surveys allow investigation of the quasar continuum over a wide range of parameters (z, L, L/LEdd) and wavelengths (radio to X-ray). I review the spectral energy distributions of quasars and how new scaling relations with physical parameters promise to take us to a deeper understanding of the quasar continuum.

scholarly journals Quantification of diesel injector dribble using 3D reconstruction from x-ray and DBI imaging

2017 ◽  
Author(s):  
Cyril Crua ◽  
Vitaliy Sechenyh ◽  
Jack Turner ◽  
Dan Sykes ◽  
Daniel J Duke ◽  
...  
Keyword(s):  
Image Processing ◽  
3D Reconstruction ◽  
Surface Area ◽  
High Speed ◽  
Argonne National Laboratory ◽  
Object Model ◽  
X Ray ◽  
Temperature Conditions ◽  
Processing Approach ◽  
Wide Range

Post-injection dribble is known to lead to incomplete atomisation and combustion due to the release of slowmoving, and often surface-bound, liquid fuel after the end of the injection event. This can have a negative effect on engine emissions, performance, and injector durability. To better quantify this phenomenon we present a new image processing approach to quantify the volume and surface area of ligaments produced during the end of injection, for an ECN ‘Spray B’ 3-hole injector. Circular approximation for cross-sections was used to estimate three-dimensional parameters of droplets and ligaments. The image processing consisted in three stages: edge detection, morphological reconstruction, and 3D reconstruction. For the last stage of 3D reconstruction, smooth surfaces were obtained by computation of the alpha shape which represents a bounding volume enveloping a set of 3D points. The object model was verified by calculation of surface area and volume from 2D images of figures with well-known shapes. We show that the object model fits non-spherical droplets and pseudo-cylindrical ligaments reasonably well. We applied our processing approach to datasets generated by different research groups to decouple the effect of gas temperature and pressure on the fuel dribble process. High-speed X-ray phase-contrast images obtained at room temperature conditions (297 K) at the 7-ID beamline of the Advanced Photon Source at Argonne National Laboratory, together with diffused back-illumination (DBI) images captured at a wide range of temperature conditions (293-900 K) by CMT Motores Térmicos, were analysed and comparedquantitatively.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4742

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