Tracy Gardner - Academia.edu (original) (raw)

Papers by Tracy Gardner

2018 ASEE Annual Conference & Exposition Proceedings

2012 ASEE Annual Conference & Exposition Proceedings

graduated from the Colorado School of Mines (CSM) with B.S. degrees in chemical engineering and p... more graduated from the Colorado School of Mines (CSM) with B.S. degrees in chemical engineering and petroleum refining (CEPR) and in mathematical and computer sciences (MCS) in 1996 and with an M.S. degree in CEPR in 1998. She then got my Ph.D. in chemical engineering, studying transport in zeolite membranes, from CU, Boulder, in 2002. She did a postdoc at TUDelft in the Netherlands in 2002 and 2003, studying oxygen conducting mixed oxide membranes and teaching reactor engineering, and she has been teaching back at CSM since 2004. I am now a Teaching Associate Professor and the Assistant Department Head of the Chemical and Biological Engineering Department at CSM. My primary research focus is in pedagogy, specifically in utilizing tablets and other technology and different teaching methods to increase student engagement and reduce/eliminate lecturing in the classroom. She likes to play with her kids, play racquetball, run, bike, swim, and play pool in her free time.

2019 ASEE Annual Conference & Exposition Proceedings

Sciences in Groningen, where he taught both in Dutch and in English. During this time his primary... more Sciences in Groningen, where he taught both in Dutch and in English. During this time his primary teaching and course development responsibilities were wide-ranging, but included running the Unit Operations laboratory, introducing Aspen Plus software to the curriculum, and developing a course for a new M.S. program on Renewable Energy (EUREC). In conjunction with his teaching appointment, he supervised dozens of internships (a part of the curriculum at the Hanze), and a number of undergraduate research projects with the Energy Knowledge Center (EKC) as well as a master's thesis. In 2016, Dr. Barankin returned to the US to teach at the Colorado School of Mines. His primary teaching and course development responsibilities here include the Unit Operations Lab and Senior Design (including Aspen), among other undergraduate core courses. His research interests include digital & online methods in engineering education. Dr. Tracy Q. Gardner, Colorado School of Mines Tracy Q. Gardner graduated from the Colorado School of Mines (CSM) with B.S. degrees in chemical engineering and petroleum refining (CEPR) and in mathematical and computer sciences (MCS) in 1996 and with an M.S. degree in CEPR in 1998. She then got her Ph.D. in chemical engineering, studying transport in zeolite membranes, from CU, Boulder, in 2002. She did a postdoc at TUDelft in the Netherlands in 2002 and 2003, studying oxygen conducting mixed oxide membranes and teaching reactor engineering, and she has been teaching back at CSM since 2004. She is now a Teaching Professor in the Chemical and Biological Engineering Department at CSM. Her primary research focus is in pedagogy, specifically in utilizing tablets and other technology and different teaching methods to increase student engagement and reduce/eliminate lecturing in the classroom. She likes to play with her kids, play racquetball, run, bike, swim, and play pool in her free time.

2013 ASEE Annual Conference & Exposition Proceedings

Increasingly affordable mobile computing devices can be used effectively to facilitate real-time ... more Increasingly affordable mobile computing devices can be used effectively to facilitate real-time formative assessment. Students equipped with pen-enabled Android devices, iPads, iPhones and/or tablet PCs can use digital ink to reveal their thinking as they construct new understandings of concepts. InkSurvey is free, web-based software (ticc.mines.edu) designed specifically for collecting student responses for real-time formative assessment. During the learning process, the instructor poses open format, embedded questions to probe student understanding. Students respond with words, drawings, graphs, or equations "inked" on either their own devices or those provided by the institution. The construction of these responses actively engages the students with the subject material and increases student metacognition. The instructor, instantaneously receiving this feedback, has a real-time glimpse into the minds of the students and can address lingering questions, repair misconceptions, and make better use of class time. We describe significant recent improvements to InkSurvey that have made it more fully functional on a greater variety of devices and more user-friendly for both instructors and students. Specific classroom examples and results are presented to illustrate student metacognition, how student thinking changes over time, and changes in instructor responses and approaches to learning. Potential use of this technology-based teaching tool outside of the traditional classroom, for example in a distance-learning environment or for Just-in-Time Teaching (JiTT), is also discussed. To provide additional context, a brief overview summarizes some of the varied applications and settings in engineering education in which the use of InkSurvey has been previously explored: increasing learning gains, improving problem-solving skills, and enhancing learning gains achieved when coupled with computer simulations. Real-time formative assessment collected with InkSurvey is blind to gender, personality biases, and other stereotypes, making it a particularly effective tool in group and cooperative learning environments. This also opens the door to additional applications in non-academic settings as well.

2020 ASEE Virtual Annual Conference Content Access Proceedings

Human–Computer Interaction Series, 2015

Membranes, 2021

Palladium and palladium alloy membranes are superior materials for hydrogen purification, removal... more Palladium and palladium alloy membranes are superior materials for hydrogen purification, removal, or reaction processes. Sieverts’ Law suggests that the flux of hydrogen through such membranes is proportional to the difference between the feed and permeate side partial pressures, each raised to the 0.5 power (n = 0.5). Sieverts’ Law is widely applied in analyzing the steady state hydrogen permeation through Pd-based membranes, even in some cases where the assumptions made in deriving Sieverts’ Law do not apply. Often permeation data are fit to the model allowing the pressure exponent (n) to vary. This study experimentally assessed the validity of Sieverts’ Law as hydrogen was separated from other gases and theoretically modelled the effects of pressure and temperature on the assumptions and hence the accuracy of the 0.5-power law even with pure hydrogen feed. Hydrogen fluxes through Pd and Pd-Ag alloy foils from feed mixtures (5–83% helium in hydrogen; 473–573 K; with and without a...

Industrial & Engineering Chemistry Research, 2005

SAPO-34 membranes on stainless steel, tubular supports separated CO 2 from CH 4 at feed pressures... more SAPO-34 membranes on stainless steel, tubular supports separated CO 2 from CH 4 at feed pressures up to 3.1 MPa. The highest CO 2 permeance was 2.4 × 10-7 mol/(m 2 s Pa) for a 50/50 feed mixture at a pressure drop of 0.14 MPa. For a pressure drop of 3 MPa, the CO 2 /CH 4 separation selectivities at 253 K were 140-150; at lower pressure drops, the highest selectivity was 270. The highest CO 2 flux was 21 kg/(m 2 h) at 295 K and a pressure drop of 3 MPa. Separation selectivity decreased as temperature increased because separation was partly based on competitive adsorption. As transmembrane pressure drop increased, both CO 2 flux and CO 2 permeate concentration increased for a 50/50 mixture. The flux pressure dependence was modeled by Maxwell-Stefan diffusion for mixtures. Methane decreased the CO 2 diffusion rate and, thus, decreased the CO 2 flux. The CH 4 flux was also lower in a mixture because CO 2 inhibits CH 4 adsorption.

Industrial & Engineering Chemistry Research, 2002

ABSTRACT Adsorption isotherms and diffusion coefficients for n-C4 and i-C4 in the transport pathw... more ABSTRACT Adsorption isotherms and diffusion coefficients for n-C4 and i-C4 in the transport pathways through tubular ZSM-5 zeolite membranes were determined over a range of temperatures by a transient permeation method. The permeate response to step changes in the feed were measured, and the transport was modeled as Maxwell−Stefan diffusion with single site Langmuir adsorption in the zeolite. The heats of adsorption and the Langmuir parameters were comparable to values reported for MFI powders. The similarity of the membrane and powder isotherms indicates that butanes diffuse mainly through zeolite pores. Maxwell−Stefan diffusion coefficients for n-C4 and i-C4 in the ZSM-5 membranes were similar to those measured by other macroscopic techniques for zeolite crystals and membranes, and diffusion coefficients increased with increasing feed partial pressure for a high-quality membrane. The effective membrane thickness was also estimated from these transient measurements.

Industrial & Engineering Chemistry Research, 2006

Transient permeation of binary mixtures through zeolite membranes was modeled by Maxwell-Stefan d... more Transient permeation of binary mixtures through zeolite membranes was modeled by Maxwell-Stefan diffusion and extended Langmuir adsorption. The permeate response of the faster-diffusing component overshoots its steady-state permeance, even when adsorption properties of the two components are identical. For zero permeate pressure and negligible support resistance, the adsorption equilibrium constants only affect the transient response by determining feed occupancies. Both higher permeate pressures and more support resistance decrease the overshoot in the permeate response of the faster-diffusing component. In some cases, molecules transport through the membranes against their concentration gradient under transient conditions because of the influence of slower-diffusing molecules. At steady-state, slower-diffusing molecules can cause faster-diffusing molecules to transport against their concentration gradient for high permeate pressures or substantial support resistance.

Desalination, 2002

Adsorption isotherms and diffision coeffkients for light gases and butane isomers were measured f... more Adsorption isotherms and diffision coeffkients for light gases and butane isomers were measured for the transport pathways involved in gas permeation through H-ZSM-5 membranes by a transient permeation technique. The permeate responses to step changes in the feed were measured, and the transport was modeled as Maxwell-Stefan diffusion with single-site Langmuir adsorption in the zeolite. Isotherms measured for N2, CO,, and CH, at 295 K were nearly identical to those measured by calorimetry on H-ZSM-5 powders. Isotherms for butane isomers were also similar to isotherms for MFI powders and heats of adsorption and diffusion activation energies were in the ranges reported in the literature. Maxwell-Stefan diffusion coeffkients for all gases studied increased slightly with feed partial pressure and were similar to those measured by other macroscopic methods for zeolite membranes and crystals. Effective membrane thicknesses were also determined non-destructively for tubular zeolite membranes by the transient permeation technique.

Journal of Membrane Science, 2007

Maxwell-Stefan models indicate that, under some conditions, fluxes through supported zeolite memb... more Maxwell-Stefan models indicate that, under some conditions, fluxes through supported zeolite membranes can be significantly higher when zeolite films are on both sides of the porous support than for a single supported film. Partial pressure drops across the support make loadings higher on the downstream side of the zeolite in the presence of a support, and the lower driving forces