Quantification Of Displacement Research Articles

Development of a novel experimental technique for the measurement of residual wall layer thickness in water-oil displacement flows

The effective removal and displacement of fluids is important in many industrial and environmental applications, such as for operation and cleaning of process equipment, fluid injection in porous media for oil recovery or aquifer remediation, or for achieving subsurface zonal isolation in new or abandoned wells. The accurate measurement of the residual fluid wall film left behind after displacement by a cleaning fluid is a long-standing challenge, particularly so for very thin fluid films where the thickness can be of the order of micrometer. We focus on the characterization of oil films left on the wall of a horizontal pipe after the pipe has been displaced by water, and develop a novel, non-intrusive analytical technique that allows the use of relevant pipe materials. The oil that originally occupies the pipe is stained by a hydrophobic dye Nile red, and an intermediate organic solvent is used to collect the residual oil volume that remains after displacing the pipe with a known volume of water. Finally, ultraviolet-visible spectroscopy is used to measure the Nile red concentration in the collected fluid, which is proportional to the residual volume of oil in the pipe. We demonstrate the methodology by conducting experiments where the displacing fluid is injected at two different imposed velocities, and where the injected fluid volume is varied. As expected, we find a gradual thinning of the oil film with increasing injected fluid volume. We compare the measured film thicknesses to a displacement model based on the steady velocity profile in a pipe, and find that experiments consistently produce smaller film thicknesses. This developed technique allows quantification of displacement and cleaning mechanisms involved in immiscible displacements at laminar, transitional and turbulent regimes, for different non-Newtonian fluid pairs, and for different realistic pipe materials and surface roughnesses.

Deformation analysis of a reference wall towards the uncertainty investigation of terrestrial laser scanners

Abstract The perfect knowledge about the scanned object’s geometry is essential for the empirical analysis of the stochastic properties of terrestrial laser scanners (TLSs). The Bonn reference wall is intended to be used as a reference for TLS quality investigations. Therefore, it is necessary to know the geometry of the wall at each time of scanning to avoid the misinterpretation of possible movements as systematic effects in the scanner. For this reason, we investigate the stability of the Bonn reference wall in this study. This includes the definition of a geodetic datum, the quantification of displacements, and the establishment of a suited deformation model. Since we discover a movement of about 1 mm within one day and up to 7 mm over the year, it is necessary to establish a cause-response deformation model to correct the wall movements in the scans. This study proposes two dynamic deformation models to compensate for the movements of the wall within one day and within a year. Our results show that it is better to measure the initial geometry of the wall each day since 89 % of the relative movements can be reduced to a maximum of 0.25 mm with a standard deviation of 0.16 mm (0.23 mm without modeling). If the shape is not initially known each day, the standard deviation of the displacements can be reduced from 1.10 mm to 0.61 mm, but the largest residuals still amount up to 2.5 mm, which is not sufficient for stochastic TLS investigations.

Multiscale modelling of the long-term performance of prestressed concrete structures – Case studies on T-Girder beams

It is well known that the long-term performance of prestressed concrete structures, i.e. the evolution of strains and stresses over time, is mainly dominated by the coupled effect of creep and shrinkage of concrete combined with the relaxation occurring in the prestressing tendons. Studies focusing on the long-term performance of real structures have been growing mainly in the last decade focusing on more efficient procedures for the design of prestressed concrete structures.This work introduces a novel bottom-up approach for the long-term analysis of T-girder prestressed beams. Two case studies are considered to support this work: (i) a small-scale beam and (ii) a full-scale double T-girder. A thorough discussion is made based on the quantification of displacements, strains and stresses in both concrete and tendons.It is found that keeping the material-related properties as invariant in the modelling, the attainment of the Serviceability Limit States is dependent on the finite element type selected to model the long-term behaviour of the structure.

Newborn crawling and rooting in response to maternal breast odor.

A growing literature shows that perception and action are already tightly coupled in the newborn. The current study aimed to examine the nature of the coupling between olfactory stimuli from the mother and the newborn's crawling and rooting (exploratory movements of the head). To examine the coupling, the crawling and rooting behavior of 28 2-day-old newborns were studied while they were supported prone on a mobility device shaped like a mini skateboard, the Crawliskate®, their head positioned directly on top of a pad infused with either their mother's breast odor (Maternal) or the odor of water (Control). Video and 3D kinematic analyses of the number and types of limb movements and quantification of displacement across the surface revealed that newborns are significantly more efficient crawlers when they smell the maternal odor, moving greater distances although performing fewer locomotor movements. In addition, the newborns made significantly more head rooting movements in the presence of the maternal odor. These findings suggest that the circuitry underlying quadrupedal locomotion and exploratory movements of the head is already adaptable to olfactory information via higher brain processing. Moreover, the coupling between olfaction and the two action systems, locomotion and rooting, is already differentiated. As crawling enables the newborn to move toward the mother's breast immediately after birth and facilitates mother-infant interaction, the results of this study highlight the potential value of using maternal odors to stimulate mobility in infants at risk of motor delay and/or deprived of this odor when born prematurely.

Quantification of displacement and particle crushing around a penetrometer tip

Particle crushing occurs near the tip of a penetrometer and influences the development of the tip resistance. To study particle crushing near a penetrometer tip, a cone penetrometer was monotonically jacked and then load-tested in medium dense and dense silica sand samples prepared in a half-cylindrical calibration chamber with viewing windows. During the tests, images of the advancing penetrometer and the surrounding soil were taken using digital cameras and analyzed to obtain the displacement and strain fields around the penetrometer using the Digital Image Correlation (DIC) technique. Subsequently, soil samples were collected near the tip of the penetrometer using a novel agar-impregnation technique and digitized using an X-ray microscope. The digitized samples were analyzed to reconstruct the three-dimensional models of individual particles, generating the gradation and relative breakage parameters of the sand around the cone penetrometer.

8. Use of the Hexamotion system coupled to Delta 4 detector for quality control of treatment plans in blocked inspiration

Introduction The blocked inspiration technique limits internal movements during CT acquisition and irradiation. This technique of respiratory control allows, especially for breast and lung cancer, to preserve the OARs (Heart, Lungs). In lung cancers, it improves the coverage and delivers more doses to the tumor without increasing the dose to OARs. Implementation of this technique requires the development of new methods of quality control for treatment plan that take account of these movements and their uncertainties. The aim is to simulate displacements between 2 breath hold inspirations representative of clinical cases and to introduce errors to better represent the uncertainty of repositioning the tumor. Then, the purpose is to evaluate the impact of these displacements on the quality of treatment plans using phantom measurements. Methods For lung and breast cancer, the displacement is quantified between the mean tumor position in respiratory cycle and its position in deep inspiration breath hold. This displacement quantification is done with ImageJ in 3D and is included in «Trajectory» file. Errors randomly generated according to Gaussian distribution are introduced in these displacements to represent intrafraction motion. A homemade program allows to apply these displacements to a 3D motion system (Hexamotion, Scandidos). A 3D phantom (Delta 4, Scandidos) placed on this system provides the evaluation of treatment plan quality and to define tolerance on patient motion. The analysis criteria are defined 3%/3 mm, local analysis and 20% dose threshold. Results Analysis on ImageJ allow to estimate offsets of 2.8 mm along the X axis, 5.3 mm along Y and −4 mm along Z. “Trajectory” files based on this displacements are generated and the uncertainties of repositioning are taken into account according to the Gaussian law. Conclusions This study provides an optimization of virtual simulation and dosimetry protocols, based on quality control results of treatment plan. It allows to define tolerances on intrafraction repositioning of blocked inspiration. Download : Download high-res image (113KB) Download : Download full-size image

Micro-CT based finite element models of cancellous bone predict accurately displacement once the boundary condition is well replicated: A validation study

Non-destructive 3D micro-computed tomography (microCT) based finite element (microFE) models are used to estimate bone mechanical properties at tissue level. However, their validation remains challenging. Recent improvements in the quantification of displacements in bone tissue biopsies subjected to staged compression, using refined Digital Volume Correlation (DVC) techniques, now provide a full field displacement information accurate enough to be used for microFE validation. In this study, three specimens (two humans and one bovine) were tested with two different experimental set-ups, and the resulting data processed with the same DVC algorithm. The resulting displacement vector field was compared to that predicted by microFE models solved with three different boundary conditions (BC): nominal force resultant, nominal displacement resultant, distributed displacement. The first two conditions were obtained directly from the measurements provided by the experimental jigs, whereas in the third case the displacement field measured by the DVC in the top and bottom layer of the specimen was applied. Results show excellent relationship between the numerical predictions (x) and the experiments (y) when using BC derived from the DVC measurements (UX: y=1.07x−0.002, RMSE: 0.001mm; UY: y=1.03x−0.001, RMSE: 0.001mm; UZ: y=x+0.0002, RMSE: 0.001 mm for bovine specimen), whereas only poor correlation was found using BCs according to experiment set-ups. In conclusion, microFE models were found to predict accurately the vectorial displacement field using interpolated displacement boundary condition from DVC measurement.

Quantification of the vocal folds’ dynamic displacements

Fast dynamic data acquisition techniques are required to investigate the motional behavior of the vocal folds (VFs) when they are subjected to a steady air-flow through the trachea. High-speed digital holographic interferometry (DHI) is a non-invasive full-field-of-view technique that has proved its usefulness to study rapid and non-repetitive object movements. Hence it is an ideal technique used here to measure VF displacements and vibration patterns at 2000 fps. Analyses from a set of 200 displacement images showed that VFs’ vibration cycles are established along their width (y) and length (x). Furthermore, the maximum deformation for the right and left VFs’ area may be quantified from these images, which in itself represents an important result in the characterization of this structure. At a controlled air pressure, VF displacements fall within the range ~100–1740 nm, with a calculated precision and accuracy that yields a variation coefficient of 1.91%. High-speed acquisition of full-field images of VFs and their displacement quantification are on their own significant data in the study of their functional and physiological behavior since voice quality and production depend on how they vibrate, i.e. their displacement amplitude and frequency. Additionally, the use of high speed DHI avoids prolonged examinations and represents a significant scientific and technological alternative contribution in advancing the knowledge and working mechanisms of these tissues.

Variable ultrasound trigger delay for improved magnetic resonance acoustic radiation force imaging

Magnetic resonance acoustic radiation force imaging (MR-ARFI) allows the quantification of microscopic displacements induced by ultrasound pulses, which are proportional to the local acoustic intensity. This study describes a new method to acquire MR-ARFI maps, which reduces the measurement noise in the quantification of displacement as well as improving its robustness in the presence of motion.Two MR-ARFI sequences were compared in this study. The first sequence ‘variable MSG’ involves switching the polarity of the motion sensitive gradient (MSG) between odd and even image frames. The second sequence named ‘static MSG’ involves a variable ultrasound trigger delay to sonicate during the first or second MSG for odd and even image frames, respectively. As previously published, the data acquired with a variable MSG required the use of reference data acquired prior to any sonication to process displacement maps. In contrary, data acquired with a static MSG were converted to displacement maps without using reference data acquired prior to the sonication. Displacement maps acquired with both sequences were compared by performing sonications for three different conditions: in a polyacrylamide phantom, in the leg muscle of a freely breathing pig and in the leg muscle of pig under apnea.The comparison of images acquired at even image frames and odd image frames indicates that the sequence with a static MSG provides a significantly better steady state (p < 0.001 based on a Student’s t-test) than the images acquired with a variable MSG. In addition no reference data prior to sonication were required to process displacement maps for data acquired with a static MSG. The absence of reference data prior to sonication provided a 41% reduction of the spatial distribution of noise (p < 0.001 based on a Student’s t-test) and reduced the sensitivity to motion for displacements acquired with a static MSG. No significant differences were expected and observed for thermal maps acquired with a variable MSG and a static MSG.The use of a static MSG with a variable ultrasound trigger delay improves the ARFI displacement map quality without additional acquisition time and remains compatible with the simultaneous acquisition of MR thermal maps.

Pelvic floor muscle displacement during voluntary and involuntary activation in continent and incontinent women: a systematic review.

Investigations of the dynamic function of female pelvic floor muscles (PFM) help us to understand the pathophysiology of stress urinary incontinence (SUI). Displacement measurements of PFM give insight into muscle activation and thus help to improve rehabilitation strategies. This systematic review (PROSPERO 2013: CRD42013006409) was performed to summarise the current evidence for PFM displacement during voluntary and involuntary activation in continent and incontinent women. MEDLINE, EMBASE, Cochrane and SPORTDiscus databases were searched using selected terminology reflecting the PICO approach. Screening of Google Scholar and congress abstracts added to further information. Original articles investigating PFM displacement were included if they reported on at least one of the aims of the review, e.g., method, test position, test activity, direction and quantification of displacement, as well as the comparison between continent and incontinent women. Titles and abstracts were screened by two reviewers. The papers included were reviewed by two individuals to ascertain whether they fulfilled the inclusion criteria and data were extracted on outcome parameters. Forty-two predominantly observational studies fulfilled the inclusion criteria. A variety of measurement methods and calculations of displacement was presented. The sample was heterogeneous concerning age, parity and continence status. Test positions and test activities varied among the studies. The findings summarise the present knowledge of PFM displacement, but still lack deeper comprehension of the SUI pathomechanism of involuntary, reflexive activation during functional activities. We therefore propose that future investigations focus on PFM dynamics during fast and stressful impact tasks.

Pelvic floor muscle displacement during voluntary and involuntary activation in continent and incontinent women: a systematic review

Investigations of the dynamic function of female pelvic floor muscles (PFM) help us to understand the pathophysiology of stress urinary incontinence (SUI). Displacement measurements of PFM give insight into muscle activation and thus help to improve rehabilitation strategies. This systematic review (PROSPERO 2013: CRD42013006409) was performed to summarise the current evidence for PFM displacement during voluntary and involuntary activation in continent and incontinent women. MEDLINE, EMBASE, Cochrane and SPORTDiscus databases were searched using selected terminology reflecting the PICO approach. Screening of Google Scholar and congress abstracts added to further information. Original articles investigating PFM displacement were included if they reported on at least one of the aims of the review, e.g., method, test position, test activity, direction and quantification of displacement, as well as the comparison between continent and incontinent women. Titles and abstracts were screened by two reviewers. The papers included were reviewed by two individuals to ascertain whether they fulfilled the inclusion criteria and data were extracted on outcome parameters. Forty-two predominantly observational studies fulfilled the inclusion criteria. A variety of measurement methods and calculations of displacement was presented. The sample was heterogeneous concerning age, parity and continence status. Test positions and test activities varied among the studies. The findings summarise the present knowledge of PFM displacement, but still lack deeper comprehension of the SUI pathomechanism of involuntary, reflexive activation during functional activities. We therefore propose that future investigations focus on PFM dynamics during fast and stressful impact tasks.

Tissue Doppler Imaging (TDI) as a New Method for Assessing Pelvic Floor Biomechanics

Tissue Doppler Imaging (TDI) is a novel parametric imaging tool that allows quantification of displacement, velocities and strain. Since today there is no established technique of quantifying pelvic floor biomechanics we investigated morphological and functional pelvic floor biomechanics by TDI.

Human Internal Disc Strains in Axial Compression Measured Noninvasively Using Magnetic Resonance Imaging

Internal deformations and strains were measured within intact human motion segments. Quantify 2-dimensional internal deformation and strain in compression of human intervertebral discs using MRI. Experiments using radiographic or optical imaging have provided important data for internal disc deformations. However, these studies are limited by physical markers and/or disruption of the disc structural integrity. MR images were acquired before and during application of a 1000 N axial compression. Two-dimensional internal displacements, average strains, and the location and direction of peak strains were calculated using texture correlation, a pattern matching algorithm. The average height loss was 0.4 mm, which corresponded to 4.4% compressive strain. The inner AF radial displacement was outward, even with degeneration; the average outward displacement of the inner AF (0.16 mm) was less than the outer AF (0.36 mm). High shear peak strains (2%-26%) occurred near the endplate and at the inner AF. Shear was higher in the anterior AF compared to the posterior. This technique allows quantification of displacement and strain within the intact disc. The radial displacements of inner AF suggest NP translation under compression. Peak tensile radial strains occurred as vertical bands throughout the anulus, which may contribute to radial tears and herniations. The tensile axial and shear strains at the interface between the AF and endplate could be related to the occurrence of rim lesions. Peak strains at the endplate are likely due to the AF curvature and the oblique fibers angle at fiber insertion sites. In the future, this technique may be used to measure disc strain under a variety of loading conditions, such as bending or torsion, and could also be used to study the mechanical effects of disc degeneration and potential clinical interventions.

Geometric and numerical model of progressive limb rotation in detachment folds

A simple, area-balanced, geometric model of progressive limb rotation in detachment folds allows the quantification of displacement, uplift, and rotation and the assessment of their effect upon growth strata geometries. Translation of this geometric model into a velocity model of deformation allows the modeling of associated growth strata resulting from background sedimentation and local erosion, transport, and deposition. We show that with constant displacement and sedimentation rate, this model predicts a progressive unconformity, indicating the onlap and eventual overlap of the fold limb caused by a decreasing uplift rate. This decrease is a consequence of the kinematics of progressive limb rotation. Increases in displacement rate, with sedimentation rate kept constant, can lead to offlap and angular unconformities, although subsequent onlap does not necessarily reflect a return to a lower displacement rate. Modeled growth strata geometries exhibit many of the features reported from the literature.