A method is proposed to fuse the information from two navigation systems whose relative position is unknown, but where there exists an upper limit on how far apart the two systems can be. The proposed information fusion method is applied to a scenario in which a pedestrian is equipped with two foot-mounted zero-velocity-aided inertial navigation systems; one system on each foot. The performance of the method is studied using experimental data. The results show that the method has the capability to significantly improve the navigation performance when compared to using two uncoupled foot-mounted systems. / <p>QC 20121221</p>

Rock grouting is performed to decrease the hydraulic conductivity around underground structures, such as tunnels and caverns. Cement grouts are often used and pumped into joint and fractures of the rock formation. Piston type pumps are mostly used for high pressure rock grouting. A pulsation effect is inevitable when using this type of pump due to the movement of the piston. The effect of this pulsation on rock grouting is yet to be known but believed to be benefi-cial for the penetration of the grout. Current flow meters used in the field are not accu-rate enough to determine the fluctuation of the flow rate when it is less than 1 l/min. In addition, currently available flow meters measure the average of the flow over a cer-tain period of time, hence the true fluctuation of the flow rate due to the pulsation of the piston remains unknown. In this paper, a new methodology, the so called ‘Ultrasound Velocity Profiling – Pressure Difference’ (UVP+PD) method has been introduced to show the pulsation effect when using a piston type pump. The feasibility of this method was successfully investigated for the direct in-line determination of the rheological properties of micro cement based grouts under field conditions (Rahman &amp; Håkansson, 2011). Subse-quently, it was also found that this method can be very efficient to measure the fluctu-ation of the flow rate for different types of pumps. From a grouting point of view the UVP+PD method can be used to synchronize the pressure and flow of a piston type pump by measuring the pulsation effect. Conse-quently it can be used as a tool for the efficiency and quality control of different types of pumps. / <p>QC 20121221</p>

Corrugated steel pipe (CSP) culverts are widely used as an economical alternative for conveying streams and small rivers through road embankments. While passage of the design flow is generally the primary goal for culvert design, consideration must also be given to maintaining connectivity within the aquatic environment for fish and other aquatic organisms. In Canada, the design criteria for fish passage through culverts are generally specified in terms of a maximum mean flow velocity corresponding to the weakest swimming fish expected to be found at a specific location. Studies have shown, however, that the velocity distribution within a CSP culvert may provide sufficient areas of lower velocity flow near the culvert boundary to allow for fish passage, even when the mean flow velocity may exceed a fishs swimming ability. Improved knowledge of the hydraulic conditions within CSP culverts, combined with research into fish swimming capabilities and preferences, may make it possible to better tailor culvert designs for fish passage while at the same time decreasing construction costs. To meet the requirements of regulators, various measures may be taken to reduce culvert flow velocities. Embedding, or setting the invert of a culvert below the normal stream bed elevation, is a simple and inexpensive method of increasing the flow area in a culvert flowing partially full, thereby decreasing flow velocity. Fish traversing through an embedded culvert benefit not only in terms of lower mean flow velocities, but also even lower flow velocities in the near boundary region. In the province of Saskatchewan culvert embedment is regularly used as a means to improve fish passage conditions. In this study, a laboratory scale model was used to study the velocity distribution within a non-embedded and embedded CSP culvert. An acoustic Doppler velocimeter was used to measure point velocities throughout the flow cross section at several longitudinal locations along the culvert. The hydraulic conditions were varied by changing the discharge, culvert slope and depth of embedment. The point velocity data were analyzed to determine patterns of velocity and turbulence intensity at each cross section, as well as along the length of the culvert. The results from the embedded culvert tests were compared with the results from the equivalent non-embedded tests, so that initial conclusions could be made regarding the use of embedment to improve conditions for fish passage. Analysis of the cross section velocity distributions showed that, even the non-embedded culvert had a significant portion of the flow area with flow velocity less than the mean velocity. The results from the embedded tests confirmed that embedding the culvert reduced the flow velocity throughout each cross section, although the effect was most significant for the cross sections located greater than one culvert diameter downstream from the inlet. This variation in effectiveness of embedment at reducing flow velocities is attributed to the length of the M1 backwater profile relative to the culvert length, and thus the differential increase in flow depth that occurred at each measurement location along the culvert. For both the non-embedded and embedded culvert the peak point magnitudes of turbulence intensity were found to be located near the culvert inlet where the flow was contracting. In terms of the cross section average turbulence intensity, in the non-embedded culvert turbulence increased with distance downstream from the inlet and was highest at the cross sections located near the culvert outlet. Embedding the culvert was found to either have no impact, or to slightly increase, the cross section average turbulence intensity near the inlet. Again, a result that is attributed to the tapering out of the M1 backwater profile at locations near the inlet under the flow conditions tested. However, beyond eight culvert diameters downstream from the inlet, embedment did result in lower cross section average turbulence intensity when compared to the non-embedded culvert. The measured velocity profiles for the non-embedded tests were found to compare well to the theoretical log-law velocity distribution using a ks value of between 0.012 m and 0.022 m, or approximately one to two times the corrugation amplitude, when the datum for analysis was considered to be located at the crest of the pipe corrugation. The cross section velocity distributions for the non-embedded tests compared very well to the model proposed by Ead et al. (2000). Based on this assessment, it appears that the Ead et al. model is potentially suitable for use in predicting the amount of the cross sectional area in a non-embedded culvert with flow velocity less than the design target for culvert fish passage design purposes. Overall, the results of the study confirm that, embedding a CSP culvert may be an effective way to improve fish passage conditions in terms of both flow velocity and turbulence intensity.

This report details a physical modeling study to investigate the flow characteristics of circular corrugated structural plate (CSP) culverts with 10% embedment and projecting end inlets using a 0.62 m diameter corrugated metal pipe under a range of flows (0.064 m3/s to 0.254 m3/s) and slopes (0%, 0.5% and 1.0%). An automated sampling system was used to record detailed velocity measurements at cross-sections along the length of the model. The velocity data was then used to develop isovel plots and observations were made regarding the effect of water depth, average velocity, boundary roughness and inlet configuration on the velocity structure. Other key aspects examined include the distribution of shear velocity and equivalent sand roughness, Manning’s roughness, an evaluation of composite roughness calculation methods, secondary currents, area-velocity relationships, the effect of embedment on maximum discharge and a simulation of model results using HECRAS. Recommendations are presented to focus future research. / October 2007

No description available.

Introduction The ocular surface provides a unique opportunity to study hemodynamics since the vessels can be visualized directly, without treatment and non-invasively. The availability of instruments to measure various hemodynamic parameters on the ocular surface in an objective manner are lacking. The quantification of red blood cell velocity, blood oxygen saturation and conjunctival redness on the ocular surface using novel, validated techniques has the potential of providing useful information about vascular physiology. The specific aims of each chapter are as follows: Chapter 3: The objective was to design, develop and validate a system that would non-invasively quantify the red blood cell velocity in the conjunctival vessels. A tool was developed to automatically analyze video sequences of conjunctival vessels, digitally imaged with high enough magnification to resolve movement of the blood within the vessel. Chapter 4: The objective was to: a) design and develop a method in order to non-invasively quantify the changes in blood oxygen saturation (SO2) in the conjunctival vessels and demonstrate reliability of the measures and, b) demonstrate the application of the method by showing a response to an isocapnic hyperoxic provocation and compare those values to the results from a valid instrument. Chapter 5: The aim of this experiment was to examine variations in ocular redness levels, red blood cell velocities and oxygen saturation levels over time in clinically healthy participants and also to compare differences between two age groups. Chapter 6: The aim of this experiment was to examine the ocular redness levels, red blood cell velocities and oxygen saturation levels in clinically healthy participants when a topical ophthalmic decongestant was instilled onto the eye and to demonstrate the validity of the use of two novel techniques. Chapter 7: The aim of this experiment was to examine ocular redness, red blood cell velocity and oxygen saturation in participants who were habitual soft contact lens wearers (study) compared to those that did not (control) and also to compare differences in silicone (SH) and non-silicone hydrogel wearers. Methods Chapter 3: Simulations representing moving RBCs within a vessel and the random variation of each cell in terms of speed, shape and intensity were created in order to evaluate the performance of the algorithm. For each vessel, a signal that correlated to blood cell position was extracted from each frame, and the inter-frame displacement was estimated through a modified dynamic time warping (DTW) algorithm. This provided the red blood cell velocity over time in each point of the vessels. Thus, from these estimates, the mean red blood cell velocity for each vessel was easily evaluated. The true mean velocity from the simulation with the one estimated by the algorithm was compared and the system accuracy was determined. Chapter 4: a) Conjunctival vessels were imaged with two narrow-band interference filters with O2-sensitive and O2-insensitive peak transmissions using a Zeiss slit lamp at 32x magnification. Optical densities were calculated from vascular segments using the average reflected intensities inside and outside the vessels. Optical density ratios were used to calculate relative oxygen saturation values. Video images of the bulbar conjunctiva were recorded at three times of the day. Measurement repeatability was assessed over location at each time and across consecutive frames. b) Subjects initially breathed air for 10 minutes followed by pure oxygen (O2) for 20 minutes, and then air for a final 10 minute period using a sequential re-breathing circuit. Simultaneously, SO2 values measured with a pulse oximeter ear clip and finger clip were recorded. The validity of the dual wavelength method was demonstrated by comparing the values to those from the ear clip pulse oximeter. Chapter 5: Participants attended eight separate visits over the course of a day. Levels of bulbar conjunctival redness, red blood cell velocity and blood oxygen saturation were measured on a vessel of interest. Chapter 6: Participants attended three separate visits during an allotted 60 minute session. Bulbar conjunctival redness, red blood cell velocity and blood oxygen saturation were measured on a vessel of interest, pre-insertion, just after insertion and, 10 minutes after insertion of a topical ocular decongestant. Significant differences between the three measures were assessed and correlations between the three parameters were reported. Chapter 7: Participants were measured 8 times over the course of a day with their contact lenses in place. Bulbar conjunctival redness, red blood cell velocity and blood oxygen saturation were measured. Results Chapter 3: Results for the simulated videos demonstrated a very good concordance between the estimated and actual velocities supporting its validity. The mean relative error for the modified Dynamic Time Warping (DTW) method is 6%. Chapter 4: The intraclass correlations (ICCs) between the three locations at each time point were 0.93, 0.56 and 0.86 respectively. Measurements across 5 consecutive frames showed no significant difference for all subjects (ICC = 0.96). The ICCs between the two methods at each time point were 0.45, 0.10 and 0.11 respectively. a) There was no significant difference in SO2 between the three locations measured using the dual wavelength method for all subjects. There was also no significant difference between the three locations at any of the time points for the dual wavelength method. b) In response to isocapnic hyperoxic provocation using the dual wavelength method, blood oxygen saturation was increased from control values and subsequently recovered after withdrawal of hyperoxia. Blood oxygen saturation values recorded from the ear clip and finger clip of the pulse oximeter also showed an increase from control values and subsequently recovered after withdrawal of hyperoxia. SO2 comparison between the dual wavelength method and the ear-clip pulse oximeter method did not show a significant difference. The interaction between the two methods and time on SO2 was not significant. Chapter 5: From baseline, the group mean redness and oxygen saturation did not change significantly over time. There was a significant difference in the group mean red blood cell velocity values over time. There was no significant difference between age strata for all three measures. Chapter 6: After drop instillation redness values decreased significantly. There was no change in red blood cell velocity and oxygen saturation over time. There was a moderate significant correlation between SO2 and red blood cell velocity just after drop insertion. Chapter 7: When comparing the study and control groups, no significant difference in redness or SO2 over time was found. RBC velocity over time was found to be significantly different between groups. When comparing the two study groups (SH vs. hydrogel) no significant difference across either measure over time was found. Conclusions Chapter 3: Signal displacement estimation through the DTW algorithm can be used to estimate mean red blood cell velocity. Successful application of the algorithm in the estimation of RBC velocity in conjunctival vessels was demonstrated. Chapter 4: The application of the dual wavelength method was demonstrated and optical density ratios can be used in a reliable manner for relative oxygen saturation measurements. This valid method promises to enable the study of conjunctival O2 saturation under various experimental and physiological conditions. Chapter 5: The results of this study support the theory of metabolic regulation. The lack of any significant change across time for redness and oxygen saturation along with significant changes in red blood cell velocity substantiates this notion. Chapter 6: This study supports the literature regarding metabolic regulation of the microvasculature during the use of various stimuli. The results demonstrated that oxygen saturation levels remain stable even when a significant decrease in ocular redness is measured. The novel techniques used in this experiment demonstrated the expected action of the decongestant further contributing to their application and validity. Chapter 7: In summary, the participants in the study group were habitual contact lens wearers that had lower RBC velocities when compared to the control group supporting the notion that contact lenses initiate a hypoxic response. The lack of change in SO2 in either group supports the theory of metabolic regulation.

A novel electrostatic analyzer (ESA) simulation method that differs significantly from traditional methods is presented in this study, the "reverse-fly" simulation method. The simulation process and its applications are discussed in detail. This method is tested by comparing its results to the published test data of three experimental instruments; The Proton Electrostatic Analyzer-High Geometric Factor (PESA-H) instrument on the Wind mission [Lin, et al. 1995], the 2π-Toroidal Analyzer (2πTA) of Young, et al., [1988], and the Hot Plasma Composition Analyzer (HPCA) to be used in the upcoming Magnetospheric Multi-scale (MMS) mission. The strong agreement between simulation and experimental results verifies the accuracy of this technique. Our results reveal detailed properties of ESA response that are not practical to assess using laboratory data. This simulation method then is used to compare the transmission characteristics of five published ESA geometries to efficiently determine the optimal ESA geometry for use in future space missions. We show that the simulation methods described here are an important contribution to instrument design and development techniques and are critical to efficient and accurate verification of instrument performance.

Introduction The ocular surface provides a unique opportunity to study hemodynamics since the vessels can be visualized directly, without treatment and non-invasively. The availability of instruments to measure various hemodynamic parameters on the ocular surface in an objective manner are lacking. The quantification of red blood cell velocity, blood oxygen saturation and conjunctival redness on the ocular surface using novel, validated techniques has the potential of providing useful information about vascular physiology. The specific aims of each chapter are as follows: Chapter 3: The objective was to design, develop and validate a system that would non-invasively quantify the red blood cell velocity in the conjunctival vessels. A tool was developed to automatically analyze video sequences of conjunctival vessels, digitally imaged with high enough magnification to resolve movement of the blood within the vessel. Chapter 4: The objective was to: a) design and develop a method in order to non-invasively quantify the changes in blood oxygen saturation (SO2) in the conjunctival vessels and demonstrate reliability of the measures and, b) demonstrate the application of the method by showing a response to an isocapnic hyperoxic provocation and compare those values to the results from a valid instrument. Chapter 5: The aim of this experiment was to examine variations in ocular redness levels, red blood cell velocities and oxygen saturation levels over time in clinically healthy participants and also to compare differences between two age groups. Chapter 6: The aim of this experiment was to examine the ocular redness levels, red blood cell velocities and oxygen saturation levels in clinically healthy participants when a topical ophthalmic decongestant was instilled onto the eye and to demonstrate the validity of the use of two novel techniques. Chapter 7: The aim of this experiment was to examine ocular redness, red blood cell velocity and oxygen saturation in participants who were habitual soft contact lens wearers (study) compared to those that did not (control) and also to compare differences in silicone (SH) and non-silicone hydrogel wearers. Methods Chapter 3: Simulations representing moving RBCs within a vessel and the random variation of each cell in terms of speed, shape and intensity were created in order to evaluate the performance of the algorithm. For each vessel, a signal that correlated to blood cell position was extracted from each frame, and the inter-frame displacement was estimated through a modified dynamic time warping (DTW) algorithm. This provided the red blood cell velocity over time in each point of the vessels. Thus, from these estimates, the mean red blood cell velocity for each vessel was easily evaluated. The true mean velocity from the simulation with the one estimated by the algorithm was compared and the system accuracy was determined. Chapter 4: a) Conjunctival vessels were imaged with two narrow-band interference filters with O2-sensitive and O2-insensitive peak transmissions using a Zeiss slit lamp at 32x magnification. Optical densities were calculated from vascular segments using the average reflected intensities inside and outside the vessels. Optical density ratios were used to calculate relative oxygen saturation values. Video images of the bulbar conjunctiva were recorded at three times of the day. Measurement repeatability was assessed over location at each time and across consecutive frames. b) Subjects initially breathed air for 10 minutes followed by pure oxygen (O2) for 20 minutes, and then air for a final 10 minute period using a sequential re-breathing circuit. Simultaneously, SO2 values measured with a pulse oximeter ear clip and finger clip were recorded. The validity of the dual wavelength method was demonstrated by comparing the values to those from the ear clip pulse oximeter. Chapter 5: Participants attended eight separate visits over the course of a day. Levels of bulbar conjunctival redness, red blood cell velocity and blood oxygen saturation were measured on a vessel of interest. Chapter 6: Participants attended three separate visits during an allotted 60 minute session. Bulbar conjunctival redness, red blood cell velocity and blood oxygen saturation were measured on a vessel of interest, pre-insertion, just after insertion and, 10 minutes after insertion of a topical ocular decongestant. Significant differences between the three measures were assessed and correlations between the three parameters were reported. Chapter 7: Participants were measured 8 times over the course of a day with their contact lenses in place. Bulbar conjunctival redness, red blood cell velocity and blood oxygen saturation were measured. Results Chapter 3: Results for the simulated videos demonstrated a very good concordance between the estimated and actual velocities supporting its validity. The mean relative error for the modified Dynamic Time Warping (DTW) method is 6%. Chapter 4: The intraclass correlations (ICCs) between the three locations at each time point were 0.93, 0.56 and 0.86 respectively. Measurements across 5 consecutive frames showed no significant difference for all subjects (ICC = 0.96). The ICCs between the two methods at each time point were 0.45, 0.10 and 0.11 respectively. a) There was no significant difference in SO2 between the three locations measured using the dual wavelength method for all subjects. There was also no significant difference between the three locations at any of the time points for the dual wavelength method. b) In response to isocapnic hyperoxic provocation using the dual wavelength method, blood oxygen saturation was increased from control values and subsequently recovered after withdrawal of hyperoxia. Blood oxygen saturation values recorded from the ear clip and finger clip of the pulse oximeter also showed an increase from control values and subsequently recovered after withdrawal of hyperoxia. SO2 comparison between the dual wavelength method and the ear-clip pulse oximeter method did not show a significant difference. The interaction between the two methods and time on SO2 was not significant. Chapter 5: From baseline, the group mean redness and oxygen saturation did not change significantly over time. There was a significant difference in the group mean red blood cell velocity values over time. There was no significant difference between age strata for all three measures. Chapter 6: After drop instillation redness values decreased significantly. There was no change in red blood cell velocity and oxygen saturation over time. There was a moderate significant correlation between SO2 and red blood cell velocity just after drop insertion. Chapter 7: When comparing the study and control groups, no significant difference in redness or SO2 over time was found. RBC velocity over time was found to be significantly different between groups. When comparing the two study groups (SH vs. hydrogel) no significant difference across either measure over time was found. Conclusions Chapter 3: Signal displacement estimation through the DTW algorithm can be used to estimate mean red blood cell velocity. Successful application of the algorithm in the estimation of RBC velocity in conjunctival vessels was demonstrated. Chapter 4: The application of the dual wavelength method was demonstrated and optical density ratios can be used in a reliable manner for relative oxygen saturation measurements. This valid method promises to enable the study of conjunctival O2 saturation under various experimental and physiological conditions. Chapter 5: The results of this study support the theory of metabolic regulation. The lack of any significant change across time for redness and oxygen saturation along with significant changes in red blood cell velocity substantiates this notion. Chapter 6: This study supports the literature regarding metabolic regulation of the microvasculature during the use of various stimuli. The results demonstrated that oxygen saturation levels remain stable even when a significant decrease in ocular redness is measured. The novel techniques used in this experiment demonstrated the expected action of the decongestant further contributing to their application and validity. Chapter 7: In summary, the participants in the study group were habitual contact lens wearers that had lower RBC velocities when compared to the control group supporting the notion that contact lenses initiate a hypoxic response. The lack of change in SO2 in either group supports the theory of metabolic regulation.

The study of haptics, or the sense of touch in virtual reality environments, is constantly looking for improvements in modeling with a high fidelity. Highly detailed models are desirable, but they often lead to slow processing times, which can mean a loss of fidelity in the force feedback sensations. Model compression techniques are critical to balancing model detail and processing time. One of the proposed compression techniques is to create multiple models of the same object but with different levels of detail (LOD) for each model. The technique hypothesizes that the human arm loses sensitivity to forces with the increase of its movement speed. This the compression technique determines which model to use based on the user's movement speed. This dissertation examines studies how the movement speed of the user affects the user's ability to sense changes in details of haptic models. Experiments are conducted using different haptic surfaces. Their levels of detail are changed while the subject interacts with them to mimic the effects of a multiresolution compression implementation. The tests focus on the subjects' ability to differentiate changes of the surfaces at each speed. The first experiment uses curved surfaces with multiple resolutions. This test observes the sensitivity of the user when the details on the surface are small. The results show that the subjects are more sensitive to changes of small details at a lower speed than higher speed. The second experiment measures sensitivity to larger features by using trapezoidal surfaces with different angles. The trapezoidal surfaces can be seen as a low-resolution haptic model with only two vertices, and changing the angles of the trapezoids is seen as changing the radii of curvature. With the same speed settings from the first experiment applied to the subjects, the sensitivity for changes in curvature is predicted to decrease with the increase of speed. However, the results of this experiment proved otherwise. The conclusions suggest that multiresolution designs are not a straightforward reduction of LOD, even though the movement speed does affect haptic sensitivity. The model's geometry should be taken into account when designing the parameters for haptic model compression. The results from the experiments provide insights to future haptic multiresolution compression designs.

The behavior of bubbles migrating in porous media is a critical factor in several soil remediation operations such as in situ air sparging, supersaturated water injection, bioslurping, trench aeration and up-flow operation of moving bed sand filters as well as in the oil and gas industry. Groundwater aquifers are constantly polluted by human activity and a common threat to fresh water is the contamination by non-aqueous phase liquids (NAPL). In many NAPL removal technologies, gas bubbles carrying NAPL residuals move upwards through the water-saturated porous media and thus play an essential role in contaminant recovery. The mobilization of the residual oil blobs in oil reservoirs is another important application for rising bubbles in porous media. After an oil field is waterflooded, a significant fraction of oil, referred to as waterflood residual oil, remains trapped. A potential mechanism to recover this residual oil is the mobilization of oil by gas bubbles moving upwards in water-wet systems. The main focus of this work was to measure the velocity of bubbles of various lengths during their migration through a water-wet porous medium. Experiments were conducted in a saturated glass micromodel with different test liquids, air bubbles of varying lengths and different micromodel elevation angles. More than a hundred experimental runs were performed to measure the migration velocity of bubbles as a function of wetting fluid properties, bubble length, and micromodel inclination angle. The results showed a linear dependency of the average bubble velocity as a function of bubble length and the sine of inclination angle of the model. Comparisons were made using experimental data for air bubbles rising in kerosene, Soltrol 170 and dyed White Oil. The calculated permeability of the micromodel was obtained for different systems assuming the effective length for viscous dissipation is equal to the initial bubble length. It was found that the calculated permeability had an increasing trend with increasing bubble length. Laboratory visualization experiments were conducted for air bubbles in White Oil (viscosity of 12 cP) to visualize the periodic nature of the flow of rising bubbles in a pore network. The motion of the air bubbles in saturated micromodel was video-recorded by a digital camera, reviewed and analyzed using PowerDVD ™11 software. An image of a bubble migrating in the porous medium was obtained by capturing a still frame at a specific time and was analyzed to determine the bubble shape, the exact positions of the bubble front and bubble tail during motion and, thus, the dynamic length of the bubble. A deformation in the shape of the bubble tail end was observed for long bubbles. The dynamic bubble lengths were larger than the static bubble lengths and showed an increasing trend when increasing the angle of inclination. The dynamic bubble lengths were used to recalculate the bubble velocity and permeability. A linear correlation was found for the average bubble velocity as a function of dynamic bubble length. Numerical simulation was performed by modifying an existing MATLAB® simulation for the rise velocity of a gas bubble and the induced pressure field while it migrates though porous media. The results showed that the rise velocity of a gas bubble is affected by the grid size of the pore network in the direction perpendicular to the bubble migration. In reality, this effect is demonstrated by the presence of other bubbles near the rising bubble in porous media. The simulation results showed good agreement with experimental data for long bubbles with high velocities. More work is required to improve the accuracy of simulation results for relatively large bubbles.