Science and Mechatronics Aided Research for Teachers with an Entrepreneurship Experience (SMARTER)
2013: Week V
Timothy Dennis and Peter Tsun
We are working in Professor Kim’s Applied Dynamics Lab. From the team meeting on last Thursday, we learned that the ability to determine the direction of electrical current is important to the study of work (positive and negative) in our lab.
Tim continued evaluating the INA219 chip as a method of a current measurement through a servo motor. He first tried measuring the current into the motor then he modified the servo in order to measure the current through the DC motor inside. This proved to be a challenge since the current changes direction and grounding the INA219 chip shorts the DC motor.
Peter approached current measurement from a different angle, he used a signal-conditioning circuit to determine the direction of the electrical current. Combining Peter's circuit with a current measuring circuit will result in us knowing both the magnitude and direction of the current.
Jason Rann and Charisse Nelson
Jason devoted week 5 on completing the optical microscopy of the AZ91 T4 and T6 heat treated specimens. There are inherent disadvantages to using an optical microscope though. First, there is a limit to the magnification based on the large wavelength of visible light in comparison to other light wavelengths and the wavelengths of electrons. Secondly, optical microscopes do not clearly show depth at high magnification. Because of these disadvantages of the optical microscope, Jason chose to image the specimens with an electron microscope as well.
The images were captured using the Back Scattered Electron mode which fires electrons with a high potential at the specimen. These electrons interact with the specimen and then are redirected toward a detector. The main purpose was to track precipitate migration during the heat treatments. As a heat treatment is applied, the precipitate’s migration is sped up. The microscopy shows evidence in two ways, change of size and amount of precipitates and the presence of a eutectic mixture, which is an area surrounding and connecting the precipitates that is evidence of migration. The T4 specimen showed evidence of smaller precipitates and a smaller amount. The T6 specimen showed the eutectic mixture. This optical and electron microscopy data will be correlated with hardness testing data taken in previous weeks to determine how the strength of the alloy changes when exposed to different heat treatments.
After completing Strain Rate Sensitivity for all 54 of her samples, Charisse turned the data from the tests into Stress-Strain graphs. The purpose of these graphs is to show the amount of force (or stress), it takes to change the sample length (or strain), over a given amount of time, i.e, strain rate. Three different strain rates were applied: 0.0001 s-1, 0.001 s-1, and 0.01s-1, which corresponded to the longest tests lasting over an hour and 45 minutes and the shortest test done in less than 5 minutes. The peak point on the graph represents the point where the sample has become deformed and can no longer retain its originally elastic state. After finishing the analysis of the stress-strain graphs for all the samples, Charisse will be able to tell what effect density of microballoons and strain rate have on the different syntactic foams she created.
Channa Comer and Dwight Young
We are continuing our research in Professor Profiri’s Dynamical Systems Lab. We are working on the air quality module for the Brooklyn Atlantis Project ARV. We successfully completed building the circuitry for air quality sensor array (measuring Nitrogen dioxide, Volatile Organic Compounds, and Ozone). We also finished the associated programming to convert the analog readings from the sensors to Ohms.
Next, we tested the sensors outdoors to establish a baseline sensor reading in ambient air. These measurements were used, in conjunction with logarithmic curves provided by the sensor datasheets, to determine values for the readings in parts per million (ppm) for each of the gases.
To enhance stability of the module, the circuits will be printed and sensors will be soldered to the circuit board. We also completed the assembly of a sensor array to collect relative humidity, temperature, and barometric pressure.
Kelly Brandon, Alexa Goldstrom, Zulficar Habib, and Jigar Jadav
During week 5, Kelly adapted a K Nearest Neighbors (KNN) algorithm with threshold analysis to improve face recognition and incorporate face learning.
Jigar has gotten the Raspberry Pi (Rpi) setup to run openCV 2.4.2 for Kelly’s computer visions program. He has also configured the Secure Shell (SSH) server and Virtual Network Connection (VNC) server setup on the Rpi to connect it over Wi-Fi from any of the computers on the "MechaNetwork". A webcam has also been setup to capture and display video from the camera through openCV library. Results look promising at 320x240 resolution or below. Anything higher than that produces an upwards of 1 sec. lag in streaming the video.
Alexa worked with both Auto Desk Inventor and Solid Works to model the metal neck parts and assemble them. She also researched other robot necks and the human neck to help determine the final design of CAESAR’s neck.
Zulficar worked with a 3DOF robotic arm to move it vertically and horizontally and get the arm to respond to input commands from a Flexiforce sensor. He also integrated an RSA encryption/decryption software with his under-development Android app. Finally, he successfully configured a Wifly shield to communicate wirelessly with an Arduino board.
Linda Dombi and Jason Econome
We are continuing or research in Prof. Iskander’s Soils Lab. This week we enjoyed some success! The plants (Schefflera elegantissima, Dracaena reflexa) that we used to build the first few transparent soil prototypes are still standing. It’s difficult to quantify any new root growth but other indicators such as a firm stem and green, turgid leaves tells us the plants have adapted to this new environment.
These species succeeded because they possess an innate ability to grow quickly in a saturated soil. For the moment sucrose has been removed from the transparent soil formula because although it enhances transparency, raising the beads’ refractive index closer to 1.33 (H2O), it invites microbial contamination for some plants.
The nitrogen and phosphorus enriching fertilizer (0.5 g/l) and immunity-stimulating aspirin (0.2 g/l) are promoting growth in the transparent soil as the literature suggests. There’s excitement and anticipation growing around the germinating grass seeds. Their long, white roots are not only penetrating the natural topsoil but actually invading the Aquabeads! We will quantify the growing, branching roots on a daily basis.
Further we have ordered other types of water-based beads in an effort to improve transparency of the soil. We continue researching ways to incorporate fused quartz into the transparent soil experiments.
