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2010

Memorization or understanding: are we teaching the right thing?, at Speaker Series in Mathematics Education, University of Connecticut (Storrs, CT), Thursday, September 23, 2010:
talk_1659.pdf
Education is more than just transfer of information, yet that is what is mostly done in large introductory courses -- instructors present material (even though this material might be readily available in printed form) and for students the main purpose of lectures is to take down as many notes as they can. Few students have the ability, motivation, and discipline to synthesize all the information delivered to them. Yet synthesis is perhaps the most important -- and most elusive -- aspect of education. I will show how shifting the focus in lectures from delivering information to synthesizing... Read more about Memorization or understanding: are we teaching the right thing?
Black silicon: silicon sees the light, at Graduate Consortium on Energy and Environment Seminar, Harvard University (Cambridge, MA), Friday, September 17, 2010:
talk_1684.pdf
Shining intense, ultrashort laser pulses on the surface of a crystalline silicon wafer drastically changes the optical, material and electronic properties of the wafer. The resulting textured surface is highly absorbing and looks black to the eye. The properties of this 'black silicon' make it useful for a wide range of commercial devices. In particular, we have been able to fabricate highly-sensitive PIN photodetectors using this material. The sensitivity extends to wavelengths of 1600 nm making them particularly useful for applications in communications and remote sensing.
Engaging students one-on-one, all at once; Online Session 2, at Online Short Course, The University of Pretoria in South Africa (Cambridge, MA), Thursday, September 9, 2010:
talk_1687.pdf
This short-course introduces participants to the ideas of Peer Instruction (PI) and Just- in-Time-Teaching (JiTT), two research-based methods for engaging students, improving conceptual understanding, increasing retention in courses and programs, and enhancing academic performance. Participants will also learn about a new approach to instructional design. Finally, participants will apply the knowledge gained to a specific course module they are (or will be) teaching, by re-designing (or designing) the syllabus for this course module and developing a plan for implementing PI and JiTT. The... Read more about Engaging students one-on-one, all at once; Online Session 2
Black silicon: engineering an intermediate band in silicon for photovoltaic applications, at 240th National Meeting of the American Chemical Society (Boston, MA), Wednesday, August 25, 2010:
talk_1614.pdf
Shining intense, ultrashort laser pulses on the surface of a crystalline silicon wafer drastically changes the optical, material and electronic properties of the wafer. The resulting textured surface is highly absorbing and looks black to the eye. The properties of this 'black silicon' make it useful for a wide range of commercial devices, from highly-sensitive PIN photodetectors to photovoltaics.
Infrared absorption limits of femtosecond laser doped silicon – effect of dopant types and thermal treatments, at Black Silicon Symposium (Albany, NY), Friday, August 20, 2010
Silicon doped with non-equilibrium concentrations of chalcogen exhibits strong sub-bandgap photon absorption. In this work, we investigate mid-infrared absorption of femtosecond laser doped silicon. Fourier transform infrared spectroscopy could shed light on energy levels of dopant states or bands. We study samples doped with sulfur, selenium and tellurium. In addition, we also investigate the effect of annealing temperature. Preliminary results suggest that near-unity absorption of sulfur doped silicon extends to mid-infrared. However, absorption decreases for photons with energy less than... Read more about Infrared absorption limits of femtosecond laser doped silicon – effect of dopant types and thermal treatments
Engaging students one-on-one, all at once; Online Session 1, at Online Short Course, The University of Pretoria in South Africa (Cambridge, MA), Thursday, August 19, 2010:
talk_1686.pdf
This short-course introduces participants to the ideas of Peer Instruction (PI) and Just- in-Time-Teaching (JiTT), two research-based methods for engaging students, improving conceptual understanding, increasing retention in courses and programs, and enhancing academic performance. Participants will also learn about a new approach to instructional design. Finally, participants will apply the knowledge gained to a specific course module they are (or will be) teaching, by re-designing (or designing) the syllabus for this course module and developing a plan for implementing PI and JiTT. The... Read more about Engaging students one-on-one, all at once; Online Session 1
The make-believe world of real-world physics, at Universidad de Costa Rica (San Jose, Costa Rica), Friday, August 6, 2010:
talk_1654.pdf
That physics describes the real world is a given for physicists. In spite of tireless efforts by instructors to connect physics to the real world, students walk away from physics courses believing physicists live in a world of their own. Are students clueless about the real world? Or are we perhaps deluding ourselves and misleading our students about the real world?
Investigación como base para el diseño de cursos, at Universidad de Costa Rica (San Jose, Costa Rica), Thursday, August 5, 2010:
talk_1645.pdf
Discussions of teaching -- even some publications -- abound with anecdotal evidence. Our intuition often supplants a systematic, scientific approach to finding out what works and what doesn't work. Yet, research is increasingly demonstrating that our gut feelings about teaching are often wrong. In this talk I will discuss some research my group has done on gender issues in science courses and on the effectiveness of classroom demonstrations.
Wrapping light around a hair, at Universidad de Costa Rica (San Jose, Costa Rica), Wednesday, August 4, 2010:
talk_1689.pdf
Can light be guided by a fiber whose diameter is much smaller than the wavelength of the light? Can we mold the flow of light on the micrometer scale so it wraps, say, around a hair? Until recently the answer to these questions was �no�. We developed a technique for drawing long, free-standing silica wires with diameters down to 50 nm that have a surface smoothness at the atomic level and a high uniformity of diameter. Light can be launched into these silica nanowires by optical evanescent coupling and the wires allow low-loss single-mode operation. They can be bent sharply, making it... Read more about Wrapping light around a hair
Peer Instruction: a hands-on workshop, at Universidad de Costa Rica (San Jose, Costa Rica), Wednesday, August 4, 2010:
talk_1688.pdf
The basic goals of Peer Instruction are to encourage and make use of student interaction during lectures, while focusing students' attention on underlying concepts and techniques. The method has been assessed in many studies using standardized, diagnostic tests and shown to be considerably more effective than the conventional lecture approach to teaching. Peer Instruction is now used in a wide range of science and math courses at the college and secondary level. In this workshop, participants will learn about Peer Instruction, serve as the �class� in which Peer Instruction is demonstrated... Read more about Peer Instruction: a hands-on workshop

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