Tunable band gap in Bi(Fe1−xMnx)O3 films

In order to investigate band gap tunability in polar oxides, we measured the optical properties of a series of Bi(Fe1−xMnx)O3 thin films. The absorption response of the mixed metal solid solutions is approximately a linear combination of the characteristics of the two end members, a result that demonstrates straightforward band gap tunability in this system

Characterization of a Computational Fluid Dynamics Thermocouple Model Subjected to Stochastic Environmental Forcing Using Moment Based Analysis

With increasing requirements for model validation when comparing computational and experimental results, there is a need to incorporate detailed representations of measurement devices within the computational simulations. Thermocouples are the most common temperature measurement transducers in flames and fire environments. Even for the relatively simple thermocouple transducer, the coupling of heat transfer mechanisms particularly under unsteady flow conditions leads to interesting dynamics. As experimentalists are well aware, the experimentally determined thermocouple values are not the same as the local gas temperatures and corrections are often required. From the computational perspective, it is improper then to assume that the predicted gas temperatures should be the same as the temperatures that an experimentalist might measure since the thermal characteristics of the thermocouple influence the indicated temperature. The thermal characteristics of simulated thermocouples in unsteady flame conditions are investigated. Validation exercises are presented to test the underlying thermocouple model. The thermocouple model problem is examined for a quasi-steady problem in which the gas temperature and surrounding walls are assumed to be random and described by probability density functions (PDFs). Differences are noted between the predicted thermocouple response and expected response. These differences are interpreted from the perspective of what modeling artifacts might drive the differences

Applications of heat transfer fundamentals to fire modeling

The fire industry relies on fire engineers and scientists to develop materials and technologies used to either resist, detect, or suppress fire. While combustion processes are the drivers for what might be considered to be fire phenomena, it is heat transfer physics that mediate how fire spreads. Much of the knowledge of fire phenomena has been encapsulated and exercised in fire modeling software tools. Over the past 30 years, participants in the fire industry have begun to use fire modeling tools to aid in decision making associated with design and analysis. In the rest of this paper we will discuss what the drivers have been for the growth of fire modeling tools; the types of submodels incorporated into such tools; the role of model verification, validation, and uncertainty propagation in these tools; and possible futures for these types of tools to best meet the requirements of the user community. Throughout this discussion, we identify how heat transfer research has supported and aided the advancement of fire modeling

Undergraduate research opportunities in neutron activation analysis for local, regional and international students

Neutron activation analysis (NAA) remains an excellent technique to introduce undergraduate students to nuclear science and engineering coming from different academic areas. The NAA methods encompass an appreciation of basic reactor engineering concepts, radiation safety, nuclear instrumentation and data analysis. At the Nuclear Engineering Teaching Lab at the University of Texas at Austin we have continued to provide opportunities through outreach programs to Huston-Tillotson University in Austin and Florida Memorial University in Miami Gardens, both Historically Black Colleges and Universities, and Southwestern University in Georgetown, Texas. Furthermore, in the past four years we have established a strong educational collaboration with the A parts per thousand cole Nationale Sup,rieure d'Ing,nieurs de Caen (ENSICAEN), France. Undergraduate students at ENSICAEN are required to have an internship outside of France. While many of the students stay in neighboring European countries others have chosen the United States. The cornerstone of these programs is to secure a relationship with each institution through clear educational and research objectives and goals