Development of wireless bruxism monitoring device based on pressure-sensitive polymer composite

A wireless pressure sensing bite guard has been developed for monitoring the progress of bruxism (teeth grinding during sleep); as well as protecting the teeth from damages. For sensing the pressure effectively in the restricted space and hostile environment, a pressure sensitive polymer composite has been fabricated and encapsulated into a conventional bite guard which is safe for in-situ applications. The device is anticipated to give real-time data through wireless data transmission and to have a long working life (weeks). A microcontroller-based electronic circuit has been built in-house for data collection and transmission. A low power approach is configured to increase the working life of the device. This device is a useful tool for understanding and treating bruxism

Identification of the Emergent Leaders within a CSE Professional Development Program

The need for high quality, sustainable Computer Science Education (CSE) professional development (PD) at the grades K-12 level is essential to the success of the global CSE initiatives. This study investigates the use of Social Network Analysis (SNA) to identify emergent teacher leaders within a high quality CSE PD program. The CSE PD program was designed and implemented through collaboration between the computer science and teacher education units at a Midwestern metropolitan university in North America. A unique feature of this specific program is in the intentional development of a social network. This study discusses the importance of social networks, the development of social capital, and its impact on the sustainability of the goals of the CSE PD program. The role of emergent teacher leaders in the development of the social capital of the CSE PD cohort is investigated using SNA techniques. The cohort consisted of 16 in-service teachers in grades 6-12 representing seven districts and four distinct content areas. The instruments used involved a questionnaire and the results of a CSE PD program online course. The findings suggest a correlation between the emergent teacher leaders, the online course results, and the overall cohort social capital. Future uses of SNA within professional development programs are also discussed

2018 Scholars at Work Conference Program

Program for the 2018 Scholars at Work Conference at Minnesota State University, Mankato on March 30, 2018

Tubular and sector heat pipes with interconnected branches for gas turbine and/or compressor cooling

Designing turbines for either aerospace or power production is a daunting task for any heat transfer scientist or engineer. Turbine designers are continuously pursuing better ways to convert the stored chemical energy in the fuel into useful work with maximum efficiency. Based on thermodynamic principles, one way to improve thermal efficiency is to increase the turbine inlet pressure and temperature. Generally, the inlet temperature may exceed the capabilities of standard materials for safe and long-life operation of the turbine. Next generation propulsion systems, whether for new supersonic transport or for improving existing aviation transport, will require more aggressive cooling system for many hot-gas-path components of the turbine. Heat pipe technology offers a possible cooling technique for the structures exposed to the high heat fluxes. Hence, the objective of this dissertation is to develop new radially rotating heat pipe systems that integrate multiple rotating miniature heat pipes with a common reservoir for a more effective and practical solution to turbine or compressor cooling. In this dissertation, two radially rotating miniature heat pipes and two sector heat pipes are analyzed and studied by utilizing suitable fluid flow and heat transfer modeling along with experimental tests. Analytical solutions for the film thickness and the lengthwise vapor temperature distribution for a single heat pipe are derived. Experimental tests on single radially rotating miniature heat pipes and sector heat pipes are undertaken with different important parameters and the manner in which these parameters affect heat pipe operation. Analytical and experimental studies have proven that the radially rotating miniature heat pipes have an incredibly high effective thermal conductance and an enormous heat transfer capability. Concurrently, the heat pipe has an uncomplicated structure and relatively low manufacturing costs. The heat pipe can also resist strong vibrations and is well suited for a high temperature environment. Hence, the heat pipes with a common reservoir make incorporation of heat pipes into turbo-machinery much more feasible and cost effective

Thermal conductivity and thermal diffusivity of fullerene-based nanofluids

Owing to their outstanding characteristics, carbon based nanofluids (CbNFs) have been applied to various advanced heat transfer and cooling technologies. It was claimed that these CbNFs can considerably improve the properties of the base working fluids. Among all the thermal characteristics, the thermal conductivity (lambda) is regarded as the primary parameter to be considered for the application of nanofluids (NFs). In the present research study we measured for the first time both lambda and thermal diffusivity (a(T)) of very stable fullerene (C-60)-based NFs in liquid phase (1,2,3,4-tetrahydronaphthalene and 1,2-dicholorobenzene) by the transient multi-current hot wire technique at atmospheric pressure in a wide range of temperature (254-323 K). Similar to the base liquids (BLs), we observed a slight decrease in lambda with an increase in temperature. Additionally, compared to the BLs lambda was reduced upon the addition of C-60. The results were compared with the predicted ones using different theoretical models. Not much variation in a(T) was observed between the C-60 NFs and the corresponding BLs due partly to the small variation of lambda with the addition of C-60

Toward a high resolution real gas finite volume solver with multi optimal order detection

The accurate predictions of the ORC expander performance rely on validated numerical tools that take into account the full complexity of the underlying physics. The expansion of organic vapor in turbomachines rotor and stator features non-ideal gas behavior with chocked flow in transonic conditions and supersonic expansion. In this paper, a finite volume solver using moving least squares approximations for higher order reconstruction is used. The real gas properties are taken into account using lookup tables with Tabular Taylor Series Expansion. The SLAU approximate Riemann solver is used for its compatibility with real gas computations. The conventional/classical slope limiter approach to handle shocks is replaced with the a posteriori paradigm for the local order reduction (MOOD). The developments are validated by comparing available solution of supersonic expansion of R245fa in a converging diverging nozzle test case.%ideal gas then real Further developments will focus on the CFD of turbulent non ideal dense gas expansions with implicit large eddy scale techniques using MOOD and automatic dissipation adjustment (ADA) for turbomachinery applications