Is virtuality close enough to reality? A comparison of the effectiveness of simulations with traditional laboratory activities in a high school biology class

Some schools do not have ideal access to laboratory space and supplies. Computer simulations of laboratory activities can be a cost-effective way of presenting experiences to students, but are those simulations as effective at supplementing content concepts? This study compared the use of traditional lab activities illustrating the principles of cell respiration and photosynthesis in an introductory high school biology class with virtual simulations of the same activities. Additionally student results were analyzed to assess if student conceptual understanding was affected by the complexity of the simulation. Although all student groups posted average gain increases between the pre and post-tests coupled with positive effect sizes, students who completed the wet lab version of the activity consistently outperformed the students who completed the virtual simulation of the same activity. There was no significant difference between the use of more or less complex simulations. Students also tended to rate the wet lab experience higher on a motivation and interest inventory.

Micro combined heat and power laboratory development

Micro Combined Heat and Power (Micro-CHP) system produces both electricity and heat required for residential or small business applications. Use of Micro-CHP in a residential application not only creates energy and economic savings but also reduces the carbon foot print of the house or small business. Additionally, micro-CHP can subsidize its cost of operation by selling excess electricity produced back to the grid. Even though Micro-CHP remains attractive on paper, high initial cost and optimization issues in residential scale heat and electrical requirement has kept this technology from becoming a success. To understand and overcome all disadvantages posed my Micro-CHP system, a laboratory is developed to test different scenarios of Micro-CHP applications so that we can learn and improve the current technology. This report focuses on the development of this Micro-CHP laboratory including installation of Ecopower micro-CHP unit, developing fuel line and exhaust line for Ecopower unit, design of electrical and thermal loop, installing all the instrumentation required for data collection on the Ecopower unit and developing controls for heat load simulation using thermal loop. Also a simulation of Micro-CHP running on Syngas is done in Matlab. This work was supported through the donation of ‘Ecopower’ a Micro-CHP unit by Marathon Engine and through the support of Michigan Tech REF-IF grand.

The Laboratory Evaluation of Bio Oil Derived From Waste Resources as Extender for Asphalt Binder

A shortage of petroleum asphalt is creating opportunities for engineers to utilize alternative pavement materials. Three types of bio oils, original bio oil (OB), dewatered bio oil (DWB) and polymer-modified bio oil (PMB) were used to modify and partially replace petroleum asphalt in this research. The research investigated the procedure of producing bio oil, the rheological properties of asphalt binders modified and partially replaced by bio oil, and the mechanical performances of asphalt mixtures modified by bio oil. The analysis of variance (ANOVA) is conducted on the test results for the significance analysis. The main finding of the study includes: 1) the virgin bioasphalt is softer than the traditional asphalt binder PG 58-28 but stiffer after RTFO aging because bio oil ages much faster than the traditional asphalt binder during mixing and compaction; 2) the binder test showed that the addition of bio oil is expected to improve the rutting performance while reduce the fatigue and low temperature performance; 3) both the mass loss and the oxidation are important reasons for the bio oil aging during RTFO test; the mixture test showed that 1) most of the bio oil modified asphalt mixture had slightly higher rutting depth than the control asphalt mixture, but the difference is not statistically significant; 2) the dynamic modulus of some of the bio oil modified asphalt mixture were slightly lower than the control asphalt mixture, the E* modulus is also not statistically significant; 3) most of the bio oil modified asphalt mixture had higher fatigue lives than the control asphalt mixture; 4) the inconsistence of binder test results and mixture test results may be attributed to that the aging during the mixing and compaction was not as high as that in the RTFO aging simulation. 5) the implementation of Michigan wood bioasphalt is anticipated to reduce the emission but bring irritation on eyes and skins during the mixing and compaction.