Understanding Behaviors of Attendance in Supplemental Instruction and Subsequent Academic Success in a First Year Engineering Course

As student retention and four-year graduation rates are of institutional and national interest and frequently referred metrics for college success, the Supplemental Instruction (SI) program aims to reduce D’s, F’s and Q drop rates in historically difficult classes. Although previous work done by this group revealed that attending SI sessions for a firstyear course (Introduction to Electrical Engineering) positively impacted exam scores and subsequent course grades [1], the program continues to experience low participation rates. Emerging questions of student behaviors in relation to attendance at SI sessions are addressed in this article. The study utilizes a mixed-methods approach, incorporating quantitative data relating to grades and attendance with qualitative data relating to student awareness, use and perceptions about SI. These analyses serve to gain an understanding of the effects of SI and identify components of the program that students value. Quantitative data was collected in the form of session attendance logs, grade data, and student demographics. Qualitative data was collected in the form of pre- and postsurveys administered during the third and final week of the semester.Cockrell School of Engineerin

A Second Language Acquisition Toolkit for Teaching Introduction to Computing

Introduction to Computing and higher-level programming courses are common first-year engineering curricula at the university level and are key in developing logical thought processes in engineering students. Recent research has shown that employing second language acquisition (SLA) techniques to teach programming increases exam performance and student motivation compared to more classical approaches. However, the presentation of pedagogical techniques has been largely limited to higher-level languages with more intuitive linguistic analogs and has not been extended to lower-level computing course material. In this paper we present several SLA techniques and their analogs in a computing course setting and the results of implementing an SLA strategy in a first-year engineering course. Statistical analysis shows that students taught with SLA methods completed quizzes more quickly, enjoyed recitation more, and had a higher perceived value of the class when compared with students taught with non-SLA techniques.Cockrell School of Engineerin

Dilute stuffing in the pyrochlore iridate Eu2Ir2O7Eu_2Ir_2O_7

The pyrochlore Eu$_2$Ir$_2$O$_7$ has recently attracted significant attention as a candidate Weyl semimetal. The previous reports on this compound unanimously show a thermally induced metal to insulator (MI) transition, concomitant with antiferromagnetic (AFM) long-range ordering of the Ir-moments below T$_\textit{N} \sim$120 K. However, there are contradictory reports concerning the slope d$\rho/$dT of the resistivity plots ($\rho$) in the "metallic" state above the metal-insulator (MI) transition, and the value of $\rho$ in the insulating state, both of which show significant sample dependence. Here, we explore this issue by investigating six different Eu$_2$Ir$_2$O$_7$ samples with slightly varying Eu:Ir ratio. High-resolution synchrotron powder diffraction are done to probe minor variations in the cell parameters of the various Eu$_2$Ir$_2$O$_7$ samples investigated here. Specific heat (C$_p$) and magnetic susceptibility of all the samples showed long-range antiferromagnetic ordering upon cooling below T$_\textit{N} \sim$120 K. The transitions are, however, found to be smeared out for the off-stoichiometric samples. We show that the sign of d$\rho/$dT above the metal-insulator (MI) transition is highly sensitive to the unit cell length, which, in turn, depends on the level of Eu-stuffing at the Ir-site. Samples with composition close to the ideal stoichiometry (Eu : Ir $=$ 1) showed a change of sign of d$\rho/$dT from negative to positive upon cooling below a certain temperature T $^*$ $>$ T$_\textit{MI}$. With increasing Eu-stuffing T$^*$ decreased until a negative d$\rho/$dT persisted without any sign change down to T$_\textit{MI}$.Comment: 12 pages, 7 figure

Computing Teichm\"{u}ller Maps between Polygons

By the Riemann-mapping theorem, one can bijectively map the interior of an $n$-gon $P$ to that of another $n$-gon $Q$ conformally. However, (the boundary extension of) this mapping need not necessarily map the vertices of $P$ to those $Q$. In this case, one wants to find the ``best" mapping between these polygons, i.e., one that minimizes the maximum angle distortion (the dilatation) over \textit{all} points in $P$. From complex analysis such maps are known to exist and are unique. They are called extremal quasiconformal maps, or Teichm\"{u}ller maps. Although there are many efficient ways to compute or approximate conformal maps, there is currently no such algorithm for extremal quasiconformal maps. This paper studies the problem of computing extremal quasiconformal maps both in the continuous and discrete settings. We provide the first constructive method to obtain the extremal quasiconformal map in the continuous setting. Our construction is via an iterative procedure that is proven to converge quickly to the unique extremal map. To get to within $\epsilon$ of the dilatation of the extremal map, our method uses $O(1/\epsilon^{4})$ iterations. Every step of the iteration involves convex optimization and solving differential equations, and guarantees a decrease in the dilatation. Our method uses a reduction of the polygon mapping problem to that of the punctured sphere problem, thus solving a more general problem. We also discretize our procedure. We provide evidence for the fact that the discrete procedure closely follows the continuous construction and is therefore expected to converge quickly to a good approximation of the extremal quasiconformal map.Comment: 28 pages, 6 figure

On a Baleen whale landed at Hollengade, Karnataka coast

A report on the landing of a dead whale, belonging to the genus Balenoptera, on 29th April 1987 at Hollengade 7 km south of Kumta, Karnataka

Anomalous lattice contraction and emergent electronic phases in Bi-doped Eu2_2Ir2_2O7_7

We study the pyrochlore series (Eu$_{1-x}$Bi$_x$)$_2$Ir$_2$O$_7$ for $0 \leq x \leq 1$. We show that for small $x$, the lattice undergoes an anomalous contraction but the all-in/all-out and metal-to-insulator transitions remain robust, and the resistivity approaches a $1/T$ dependence at low-T, suggesting proximity to the Weyl semimetallic phase, as previously predicted theoretically. At the boundary between Eu$_2$Ir$_2$O$_7$ and Bi$_2$Ir$_2$O$_7$ a qualitatively different ground state emerges, which is characterized by its unusual metallic behavior and absence of magnetic ordering at least down to $0.02$ K.Comment: 5 Pages, 4 figure

Testing of syntroleum fuels in diesel power plants suitable for Alaska

Thesis (M.S.) University of Alaska Fairbanks, 2005Sulfur free synthetic diesel fuels can be produced using Gas to Liquid (GTL) technology, and may prove useful as a substitute for conventional diesel fuels when oil reserves are depleted. These fuels also should produce lower emissions, as the sulfur content is near zero. However, this fuel has significantly different combustion properties than conventional diesel fuels, and may require injection timing adjustments to burn cleanly. This paper presents a comparison of the exhaust emissions from synthetic diesel fuels, manufactured by the Syntroleum Corporation, and conventional diesel fuel. Documented emissions are the total hydrocarbons, carbon monoxide and oxides of nitrogen. Effects of injection timing on exhaust emission and brake specific fuel consumption (BSFC) are also discussed.Introduction -- Literature review -- Experimental set-up -- Test fuels -- Test cycles -- Test procedure -- Emissions results -- Discussion of results -- Problems encountered during experimentation -- Conclusions -- References -- Appendix A. Results from Alaska source testing