REU Projects for Summer 2005
The following are summaries of the research projects conducted during the 2005 Metrology REU, adapted from submissions by REU participants.
Frictional Forces and Areas on the Cutting Tool During Oblique Cutting
The investigation of shear and normal forces on the secondary shearing zone (tool-chip interface) is of interest. While stress distribution models exist for orthogonal cutting, oblique cutting is not well explored. Past research indicates inconsistent patterns of sticking and sliding within the contact area. This study performs several high speed oblique cutting tests on Aluminum 7075 to determine the effects of cutting velocity, tool coating and nose radius on the shear and normal forces, as well as on the regions of sticking and sliding. Experimentation showed the development of two unique sticking zones. By analyzing these two regions, this study was able to hypothesize the causes of each of these unique regions. Based on these observations, a general model is suggested characterizing the expected sticking and sliding locations dependent on cutting velocity and workpiece material. The hypothesized model also alleviates discrepancies between observations of other previous studies.
Coordinate Metrology
Manufactured parts in industry need to be tested to see if they comply with national standards. In this study, two different sampling strategies (least squares “LSQ” and linear optimization “LOPT”), three sample sizes (8, 64, 256), and two sampling strategies (Hammersley “HM” and Random “RND”) were investigated for an effective combination to inspect three basic shapes (sphere, cone, and torus). Though many studies have been conducted concerning these three shapes individually, no group comparison has been performed.
The results showed that linear optimization performed better than least-squares across all factor combinations. The Hammersley sampling strategy and sample size 64 were found to be the most effective combination regardless of shape. Further study also demonstrated that the half-torus used is extremely sensitive to the setting of the machine origin. The results presented in this paper can provide a foundation for future shape analysis to be implemented on a larger scale.
Solute Permeability and Electron Diffusion
Electron transport dynamics and solute permeability were studied for a poly[(vinylpyridine)Os(bipyridyl)2Cl2+/3+ based solution modified with and without single-walled carbon nanotubes. The redox hydrogel designed for use in enzyme electrodes, is formed by cross-linking a glucose oxidase and PVP. The goal was to identify the major contributing factors that the incorporation of SWNTs provides as they have been shown to increase current responses near 10 fold. A RDE was used for permeation studies to find kDs. kDs was determined as for electrodes coated with POs-EA and for electrodes coated with POs-EA/CNT. Cyclic Voltammetry and Chronoamperometry were used to find De. Results with Chronoamperometry determined De was for electrodes coated with POs-EA and for electrodes coated with POs-EA/CNT. Both kDs and De were found to be well over one order of magnitude larger for films modified with SWNTs. Studies were based on ?, , found at a scan rate. ? was found to have a negligible variability, among electrodes coated with POs-EA and POs-EA/CNT, suggesting that the increased current responses were due to the increased permeation of solute and electron diffusion through the films and not due to prior conjectures about the increase in electroactive area.
Laser Doppler Velocimetry
The velocity of fluid moving over a surface may be increased or decreased with physical or chemical modification of the surface. Lotus Paint has specifically gained interest as a coating because its high percentage of large molecular structures may simulate a micro-rough surface, consequently, reducing the drag of the fluid flow. Investors of industrial processes transporting fluids or textiles for repelling water (e.g. clothing, sealants) are both interested in maximizing the hydrophobic properties of their materials since exploiting this technology improves cost effectiveness and market competition. In this experiment, measurements for velocity and shear stress were made using Laser Doppler Velocimetry and particle image velocimetry. These measurements highlight the effects of slip on the walls and thus the resulting drag reduction.
Wireless Sensor Network
In recent years, wireless sensor networking has emerged as the leader in sensing for a large number of applications. A wireless sensor is currently under development at the University of Oklahoma that uses three sensors integrated on the highway to detect hazardous road conditions. This system will solve the problem of pavement maintenance and driver awareness as it will send information across the network before transmitting the data to a base station. The base station will then display the data to monitor traffic conditions. The following three sensors will be deployed to depict the conditions of the road: ice sensor, moisture sensor, and temperature sensor. In this study, the temperature sensor was tested and calibrated by cooling and heating the sensor with an environmental chamber, and comparing voltage outputs of the sensor with theoretical values. The three sensors were then integrated, and their functionality was tested using the environmental chamber in conjunction with LabVIEW (a National Instruments software program). The results from the temperature test validated the use of the sensor in the wireless network, and the integrated sensor test demonstrated the moisture and ice sensors working in parallel with each other. At this stage, the sensors are ready to be implemented in the wireless network to detect particular road conditions.
Business Case Analysis
The students were separated into three teams. Two of these teams were given the task of creating chapters for a book dedicated to teaching college level students many topics of interest for research; the topics discussed dealt with previous REU studies at the University of Oklahoma. The third team created a program using MATLAB to aid in deciding which piece of metrology equipment to purchase including factors such as range and resolution.
The students creating the chapters for the book were given previous REU reports as a starting point, as well as a proposal for a book which would discuss many topics at an undergraduate level. The students creating the program were given metrology sources and certain hardware companies as starting points. At the end of the summer, the students presented their results in three mediums: a written report, an oral presentation, and a website.
The following are summaries of the research projects conducted during the 2005 Metrology REU, adapted from submissions by REU participants.
Frictional Forces and Areas on the Cutting Tool During Oblique Cutting
The investigation of shear and normal forces on the secondary shearing zone (tool-chip interface) is of interest. While stress distribution models exist for orthogonal cutting, oblique cutting is not well explored. Past research indicates inconsistent patterns of sticking and sliding within the contact area. This study performs several high speed oblique cutting tests on Aluminum 7075 to determine the effects of cutting velocity, tool coating and nose radius on the shear and normal forces, as well as on the regions of sticking and sliding. Experimentation showed the development of two unique sticking zones. By analyzing these two regions, this study was able to hypothesize the causes of each of these unique regions. Based on these observations, a general model is suggested characterizing the expected sticking and sliding locations dependent on cutting velocity and workpiece material. The hypothesized model also alleviates discrepancies between observations of other previous studies.
Coordinate Metrology
Manufactured parts in industry need to be tested to see if they comply with national standards. In this study, two different sampling strategies (least squares “LSQ” and linear optimization “LOPT”), three sample sizes (8, 64, 256), and two sampling strategies (Hammersley “HM” and Random “RND”) were investigated for an effective combination to inspect three basic shapes (sphere, cone, and torus). Though many studies have been conducted concerning these three shapes individually, no group comparison has been performed.
The results showed that linear optimization performed better than least-squares across all factor combinations. The Hammersley sampling strategy and sample size 64 were found to be the most effective combination regardless of shape. Further study also demonstrated that the half-torus used is extremely sensitive to the setting of the machine origin. The results presented in this paper can provide a foundation for future shape analysis to be implemented on a larger scale.
Solute Permeability and Electron Diffusion
Electron transport dynamics and solute permeability were studied for a poly[(vinylpyridine)Os(bipyridyl)2Cl2+/3+ based solution modified with and without single-walled carbon nanotubes. The redox hydrogel designed for use in enzyme electrodes, is formed by cross-linking a glucose oxidase and PVP. The goal was to identify the major contributing factors that the incorporation of SWNTs provides as they have been shown to increase current responses near 10 fold. A RDE was used for permeation studies to find kDs. kDs was determined as for electrodes coated with POs-EA and for electrodes coated with POs-EA/CNT. Cyclic Voltammetry and Chronoamperometry were used to find De. Results with Chronoamperometry determined De was for electrodes coated with POs-EA and for electrodes coated with POs-EA/CNT. Both kDs and De were found to be well over one order of magnitude larger for films modified with SWNTs. Studies were based on ?, , found at a scan rate. ? was found to have a negligible variability, among electrodes coated with POs-EA and POs-EA/CNT, suggesting that the increased current responses were due to the increased permeation of solute and electron diffusion through the films and not due to prior conjectures about the increase in electroactive area.
Laser Doppler Velocimetry
The velocity of fluid moving over a surface may be increased or decreased with physical or chemical modification of the surface. Lotus Paint has specifically gained interest as a coating because its high percentage of large molecular structures may simulate a micro-rough surface, consequently, reducing the drag of the fluid flow. Investors of industrial processes transporting fluids or textiles for repelling water (e.g. clothing, sealants) are both interested in maximizing the hydrophobic properties of their materials since exploiting this technology improves cost effectiveness and market competition. In this experiment, measurements for velocity and shear stress were made using Laser Doppler Velocimetry and particle image velocimetry. These measurements highlight the effects of slip on the walls and thus the resulting drag reduction.
Wireless Sensor Network
In recent years, wireless sensor networking has emerged as the leader in sensing for a large number of applications. A wireless sensor is currently under development at the University of Oklahoma that uses three sensors integrated on the highway to detect hazardous road conditions. This system will solve the problem of pavement maintenance and driver awareness as it will send information across the network before transmitting the data to a base station. The base station will then display the data to monitor traffic conditions. The following three sensors will be deployed to depict the conditions of the road: ice sensor, moisture sensor, and temperature sensor. In this study, the temperature sensor was tested and calibrated by cooling and heating the sensor with an environmental chamber, and comparing voltage outputs of the sensor with theoretical values. The three sensors were then integrated, and their functionality was tested using the environmental chamber in conjunction with LabVIEW (a National Instruments software program). The results from the temperature test validated the use of the sensor in the wireless network, and the integrated sensor test demonstrated the moisture and ice sensors working in parallel with each other. At this stage, the sensors are ready to be implemented in the wireless network to detect particular road conditions.
Business Case Analysis
The students were separated into three teams. Two of these teams were given the task of creating chapters for a book dedicated to teaching college level students many topics of interest for research; the topics discussed dealt with previous REU studies at the University of Oklahoma. The third team created a program using MATLAB to aid in deciding which piece of metrology equipment to purchase including factors such as range and resolution.
The students creating the chapters for the book were given previous REU reports as a starting point, as well as a proposal for a book which would discuss many topics at an undergraduate level. The students creating the program were given metrology sources and certain hardware companies as starting points. At the end of the summer, the students presented their results in three mediums: a written report, an oral presentation, and a website.
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