“Stepping out of My Comfort Zone!” Learning Intercultural Communication through an Ethnographic Project

As a means of enhancing students’ intercultural communication competence, as well as applying key concepts of intercultural communication, this activity uses an ethnographic approach in order to make students appreciate various ways people differ from each other. Specifically, through observation, participation, and interview, basic ethnographic methods, students immersed themselves in a culture that is different from their own, and try to understand that culture. Ultimately, students reported that they stepped out of their comfort zones during this project, which opened their eyes to a different culture. In addition, this activity incorporated topics learned throughout the semester, which consolidated students’ understanding of the course

Investigation of Air-side Fouling of Split System Outdoor Heat Exchangers: Characterization, Performance Effects, and Frost Formation Interactions

Fouling is generally believed to have a negative impact on heat exchanger performance, and has been studied extensively. Split systems, such as those that serve typical residential air-conditioners, have an air-to-refrigerant coil located outdoors, where it is subject to many airborne fouling agents, such as grass clippings, leaves, and dust. This research project took novel approach to testing the effects of air-side fouling. Instead of applying standardized fouling agents in a laboratory test, we collected fouled outdoor coils from field-deployed air-conditioners, and tested them in a laboratory. This allowed tight control and measurement, but with real fouling. The effects on aerodynamic performance and heat transfer were assessed under two conditions: (1) while controlling airflow rate across the coil to be constant; (2) allowing the airflow rate to vary. The latter case mimics the performance of a typical split system that has a single-speed fan, in which case the fouling can reduce bulk airflow, as well as affecting the boundary layer on the heat transfer surfaces. Based upon the findings of the effects on field-fouled coils, as well as laboratory analysis of the fouling material, we developed a new fouling agent that simultaneously impacts airflow resistance and heat transfer in a way that matches the field-fouled coils. An additional question about fouling on an outdoor coil is whether it increases frost formation for heat pumps in heating mode. A set of experiments was conducted with the synthetic fouling agent to explore the interactions between fouling and frost. This paper will: show the impacts of fouling on performance of the field-fouled coils; describe the synthetic fouling agent; show results from testing new coils that were fouled with the agent; and show the results of a set of experiments on the interactions between fouling and frost formation. One surprising finding that will be discussed and explained is that air-side fouling often improves the heat transfer performance of a coil, even while bulk airflow is reduced. Although other experimenters have observed this phenomenon, it has been controversial, and led to the author’s article being widely distributed and discussed online

CO-CULTURE SYSTEM CONSISTING OF GENETICALLY ENGINEERED Synechococcus elongatus AND Escherichia coli W

Co-culture has been a rising topic in microorganism research field and it has great potential in industrial production. Thus, an attempt is made to build a co-culture system with two model organisms, Synechococcus elongatus cscB, which is a genetically engineered sucrose producing strain, and Escherichia coli ATCC 9637 and both have great potential in industrial application. After medium modification, a co-culture system is built, and it reveals that there are additional stresses on both organisms in co-culture systems. High amount of phosphate is added into the modified medium to meet Escherichia coli coli ATCC 9637 growth requirement. In such environment, pH plays a major role in sucrose production of Synechococcus elongatus cscB; phosphate addition shows toxic effects on Synechococcus elongatus cscB but improve its sucrose production; and co-culture shows both positive and negative effects on both organisms and suggests potential metabolic changes in both organisms. The conclusion is that a co-culture system consisting of Synechococcus elongatus cscB and Escherichia coli coli ATCC 9637 is feasible but may not be favorable. Primary Reader and Advisor: Dr. Michael Betenbaugh Secondary Reader

EMD: an ensemble algorithm for discovering regulatory motifs in DNA sequences

Background Understanding gene regulatory networks has become one of the central research problems in bioinformatics. More than thirty algorithms have been proposed to identify DNA regulatory sites during the past thirty years. However, the prediction accuracy of these algorithms is still quite low. Ensemble algorithms have emerged as an effective strategy in bioinformatics for improving the prediction accuracy by exploiting the synergetic prediction capability of multiple algorithms. Results We proposed a novel clustering-based ensemble algorithm named EMD for de novo motif discovery by combining multiple predictions from multiple runs of one or more base component algorithms. The ensemble approach is applied to the motif discovery problem for the first time. The algorithm is tested on a benchmark dataset generated from E. coli RegulonDB. The EMD algorithm has achieved 22.4% improvement in terms of the nucleotide level prediction accuracy over the best stand-alone component algorithm. The advantage of the EMD algorithm is more significant for shorter input sequences, but most importantly, it always outperforms or at least stays at the same performance level of the stand-alone component algorithms even for longer sequences. Conclusion We proposed an ensemble approach for the motif discovery problem by taking advantage of the availability of a large number of motif discovery programs. We have shown that the ensemble approach is an effective strategy for improving both sensitivity and specificity, thus the accuracy of the prediction. The advantage of the EMD algorithm is its flexibility in the sense that a new powerful algorithm can be easily added to the system

Developing a novel microbial host and synthetic biology tools for valorizing waste polyethylene terephthalate and lignin-derived compounds

Please click Download on the upper right corner to see the full description

Experimental Quantification of Liquid Line Temperature Drop As a Feature to Detect Liquid Line Restriction Faults in a Residential Heat Pump

Liquid line restrictions (LL) in a vapor compression refrigeration cycle cause abnormal pressure drops in the liquid line and reduce the refrigerant mass flow. Although a thermostatic expansion valve (TXV) in the system can compensate for small restrictions, larger restrictions cause the TXV to fully open, at which point the LL can create significant impacts on system performance. Furthermore, in the presence of other faults, like undercharge (UC) or non-condensable gas (NC) in the refrigerant, this impact becomes more pronounced. Therefore, effectively detecting this fault and addressing it can improve the efficiency of system and reduce the cost of operation of the air conditioning system. Existing methods to detect this fault either require a large amount of data to train a model, or apply only to a specific system, making them impractical for a technician to use in the field. The proposed method is based on the phase change of refrigerant inside the liquid line caused by LL faults. The temperature of the refrigerant drops during phase change, so the temperature difference across the liquid line can be regarded as a decoupling feature for LL faults. Four types of common installation faults -improper evaporator airflow (EA), improper refrigerant charge (CH), NC, and LL faults -were imposed on a TXV-equipped split system heat pump, individually with four different operating conditions, and simultaneously with sets of two, three and four faults at one operating condition. Testing was conducted in a set of psychrometric chambers, to tightly control the thermal environment indoors and outdoors. The decoupling feature was calculated for each of the test scenarios. The results showed that this feature is sensitive to the presence of LL faults and insensitive to other faults, either singly or collectively. In the presence of UC or NC faults, the feature became more sensitive to LL faults, but it became less sensitive in the presence of overcharge (OC) faults. The threshold for this feature varied from condition to condition, but a general threshold of 2 °C is proposed to detect severe LL faults and moderate LL faults without the presence of OC faults