River channel stability and the implications for fish habitat

The purpose of this project was to investigate various aspects of river channel stability as they relate to fish habitat. Two headwater creeks of the Credit River system, Black and Silver Creeks, and their confluent stream, the West Credit River in Southern Ontario were used in the study. Thirty-five cross-sections were established and revisited during four flow regimes, summer base flow, fall secondary peak flow, spring melt-high flow and post-spring high flow. Measurements of width, depth and temperature were taken at these times. Water samples were taken for determination of suspended sediment concentration. Channel stability was investigated in relation to three major factors: stability of the fluid, stability of the bed, and stability of the banks. Fluid stability measurements involved measuring fluid speeds vertically and laterally through each cross-section under the four flow regimes. Individual experiments at the confluence area were conducted because of some of the earlier results from other sections of creek. Information on the rates of change of discharge were determined from secondary data provided by the Water Survey of Canada. Bed stability was measured by looking at bed material particle size distribution, cross-sectional channel profiles and control reach topographical surveys which included particle marking and tracking. Bedload transport rates at the confluence area were determined under varying flow conditions. Bank stability was investigated by the use of a piece of equipment developed for this thesis, the River Bank Profiler. Volumetric changes to banks consisting of cohesive as well as cohesionless material are presented for comparative purposes. As changes in river channel stability can have a direct impact on resident fish, investigation of the biological literature was used as a framework for the geomorphological work. It became apparent that there is a direct application of fluvial geomorphology in that biologists are stating a direct need for more geomorphological work in the area of fish habitats. A conceptual framework showing the relationship between properties of fluid, bed and bank stability and the degree of interconnectedness is presented to aid both the geomorphologist and the biologist when looking at aspects of fish habitat from a geomorphological perspective

Fluid patterns, sediment pathways and woody obstructions in the Pine River, Angus, Ontario

The objective of this research was to determine the effects that woody obstructions have on flow patterns and sediment pathways in a sand-bed river in Central Ontario. The Pine River near Angus, a tributary of the Nottawasaga River, was chosen because it contained a number of woody obstructions to flow from which to choose study sites. Two reaches, one containing a trunk oriented in the direction of flow, were chosen as the study reaches. Sampling of fluid speeds through the study reaches showed that the cross-stream obstruction acted to slow fluid as it approached and exited the obstruction zone, while at the same time it increased the variability within the flow. At the downstream obstruction, flows became concentrated and accelerated as they moved through the obstruction zone, then decreased in speed and increased in variability once the obstruction was passed. Results of fluid speed patterns and direction of flow allowed for the delineation of “zones” of fluid behaviour. Bed material particle size distributions showed differences within the obstruction zones as opposed to areas unaffected by the obstructions. Particle sizes tended to increase underneath both obstructions, indicating acceleration of fluid underpassing the trunks. Near-bed transport rates showed high variability within the reaches, with the greatest rates of transport occurring where downstream-oriented trunks were nearby. Results also showed that rates of transport entering and exiting one pool were almost identical, indicating that under those conditions the pool could be considered conditionally stable. This is an important result for aquatic biologists in that it results in stable aquatic habitat. In order to test field results under controlled conditions, flume studies on cross-stream obstructions with varying flow depths were conducted. Results showed that increasing the flow depth decreased the spatial extent of the influence zones, indicating that the spatial extent of obstructed flow is depth-dependent. This has implications for management of woody debris as in-channel habitat structures. A conceptual model of flow through obstructed zones was created for study reach. Spatial extent of these zones were determined. Finally, information on the role that obstructions could play in providing habitat for aquatic organisms, as well as how woody debris may be used in bioengineering, is presented

Wet Etching and Surface Analysis of Chemically Treated InGaN Films

This paper discusses the performance of different wet chemical etchants on InGaN. It is shown that certain etchants can be used to chemically etch and remove appreciable amounts of InGaN even though the etch rate is not as high as observed for other III-V materials. The performance of etchants studied here were (i) two different ratios of HF, HNO3, (ii) cyclic usage of NH4OH followed by HCl, (iii) hot H2SO4 and H3PO4 mixture, and (iv) conc. NH4OH. The etched surfaces have then been analyzed by x-ray photoelectron spectroscopy (XPS). Different etch residues were observed on the top surface. These results suggest an alternative to reactive plasma etching or photo-enhanced electrochemical etching of InGaN type materials. Based on the observed performance of the etchants studied, it was also possible to segregate the surface cleaning protocols and etchants

PDS4: Developing the Next Generation Planetary Data System

The Planetary Data System (PDS) is in the midst of a major upgrade to its system. This upgrade is a critical modernization of the PDS as it prepares to support the future needs of both the mission and scientific community. It entails improvements to the software system and the data standards, capitalizing on newer, data system approaches. The upgrade is important not only for the purpose of capturing results from NASA planetary science missions, but also for improving standards and interoperability among international planetary science data archives. As the demands of the missions and science community increase, PDS is positioning itself to evolve and meet those demands

Microfluidic device for drug delivery

A microfluidic device is provided for delivering a drug to an individual. The microfluidic device includes a body that defines a reservoir for receiving the drug therein. A valve interconnects the reservoir to an output needle that is insertable into the skin of an individual. A pressure source urges the drug from the reservoir toward the needle. The valve is movable between a closed position preventing the flow of the drug from the reservoir to the output needle and an open position allowing for the flow of the drug from the reservoir to the output needle in response to a predetermined condition in the physiological fluids of the individual

Measuring Accuracy of Automated Parsing and Categorization Tools and Processes in Digital Investigations

This work presents a method for the measurement of the accuracy of evidential artifact extraction and categorization tasks in digital forensic investigations. Instead of focusing on the measurement of accuracy and errors in the functions of digital forensic tools, this work proposes the application of information retrieval measurement techniques that allow the incorporation of errors introduced by tools and analysis processes. This method uses a `gold standard' that is the collection of evidential objects determined by a digital investigator from suspect data with an unknown ground truth. This work proposes that the accuracy of tools and investigation processes can be evaluated compared to the derived gold standard using common precision and recall values. Two example case studies are presented showing the measurement of the accuracy of automated analysis tools as compared to an in-depth analysis by an expert. It is shown that such measurement can allow investigators to determine changes in accuracy of their processes over time, and determine if such a change is caused by their tools or knowledge.Comment: 17 pages, 2 appendices, 1 figure, 5th International Conference on Digital Forensics and Cyber Crime; Digital Forensics and Cyber Crime, pp. 147-169, 201

Micro-Fluidic Device for Drug Delivery

A microfluidic device is provided for delivering a drug to an individual. The microfluidic device includes a body that defines a reservoir for receiving the drug therein. A valve interconnects the reservoir to an output needle that is insertable into the skin of an individual. A pressure source urges the drug from the reservoir toward the needle. The valve is movable between a closed position preventing the flow of the drug from the reservoir to the output needle and an open position allowing for the flow of the drug from the reservoir to the output needle in response to a predetermined condition in the physiological fluids of the individual

Beam-beam simulation code BBSIM for particle accelerators

A highly efficient, fully parallelized, six-dimensional tracking model for simulating interactions of colliding hadron beams in high energy ring colliders and simulating schemes for mitigating their effects is described. The model uses the weak-strong approximation for calculating the head-on interactions when the test beam has lower intensity than the other beam, a look-up table for the efficient calculation of long-range beam-beam forces, and a self-consistent Poisson solver when both beams have comparable intensities. A performance test of the model in a parallel environment is presented. The code is used to calculate beam emittance and beam loss in the Tevatron at Fermilab and compared with measurements. We also present results from the studies of two schemes proposed to compensate the beam-beam interactions: a) the compensation of long-range interactions in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven and the Large Hadron Collider (LHC) at CERN with a current-carrying wire, b) the use of a low energy electron beam to compensate the head-on interactions in RHIC