August 28, 2024 Summer lab informals Written By: Claire Massey Departments: Chemical & Biological Engineering Categories: Students|Undergraduate For our graduating seniors, Summer Lab is a great experience for students to beef up their experimental skills and work on a variety of unique projects. Along with experiments and content from the course manual, students get the chance to imagine and design their own experiments. These experiments, called “informals”, give creative license to students to solve a chosen chemical engineering problem. Check out a few of them below! Coffee machine Takuma Kawamura, Shay Doty and Noah Shelander chose to design a coffee maker. The coffee make used a water tank which was kept at a designated temperature using PI control. To do this, they used an Arduino code to manipulate the “duty-cycle” setpoint of the submerged heater, or in other words, the percentage of time that the heater was on every second. A submerged temperature sensor provided feedback data to the controller allowing for real-time adjustments. The process identification and controller design required for this were good exercises in the concepts that the group learned last semester in CBE 470 – Process Dynamics and Control. They then used the final apparatus to conduct experiments to find the optimal temperature to brew coffee. They found that within the range of 160-190°F, there was an increase in coffee concentration as the temperature of water passing through the grounds increased. The group came up with this experiment when one of them joked about making a coffee maker, “after thinking about how it would actually apply to chemical engineering, we got pretty excited,” said Shelander. A peanut butter twist Jackson Jedlicka and Shao-Ting Lin had something a bit sweeter on their minds, peanut butter! Jedlicka and Lin chose to work with peanut butter and test viscosity. To determine the viscosity, they place peanut butter samples in the shape of a circle on a platform which is hooked up to a small motor. They spin the samples which deforms them. Then, by measuring the distance traveled over time based on where the samples were placed and their ending location, they can calculate the velocity value. To calculate the viscosity of the peanut butter, the use the velocity value as well as the centrifugal force of the spinning platform, and the density and height of the peanut butter samples. Color-changing paper Seniors Madison Tan and Henry Lee put their resources together to make color changing paper! They started by making their own paper using water, sodium hydroxide or bleach. Then, by applying different concentrations of hydrochloric acid with either an extremely low concentration (less than than 1 pH) or a strong concentration (pH of 2), the treated paper turns orange or teal blue respectively. They hope to continue experimenting and want to see if using a more acidic paper, it will change to green and yellow instead. Real-world reactions In their classes, students use many equations to calculate a variety of things. But when put to the test, some equations don’t always perfectly match up to the real-world results. In summer lab, all students work on a reactor to get hands-on experience with how fluid moves through the reactor. By doing this, students can see for themselves how the results can vary from what an equation might tell them. From there, students do tests to try and adjust standard equations to match the specific reactor. This type of experience is extremely helpful for the students as they graduate and enter the industry or pursue research.