New synthetic methodologies utilizing reductive cyclizations catalyzed or mediated by titanocene complexes

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1997.Includes bibliographical references (leaves 133-137).by Natasha M. Kablaoui.Ph.D

Characterization of the performance of electromagnetic pulse-driven arrays

Numerical modeling of the beams generated from an ultra-wide bandwidth pulse-driven dipole array is considered. Several multi-derivative systems are simulated with these numerical results. The analytic performance bounds on energy, intensity, and beam width of the pulsed beams generated by the pulse driven array are derived. Numerical comparisons are made between the pulsed beams generated by driving the dipole array with monochromatic continuous waves with two distinctive amplitude tapers, Gaussian pulses with two distinctive amplitude tapers, and three types of localized waves. The specific localized waves used include the modified power spectrum pulse and the 1/2 and 3/2 superluminal pulses. The energy pattern of the pulse-driven dipole array is studied for each of these cases. The effect of element density on these energy patterns is also examined. The results obtained show that the modified power spectrum pulse truly outperforms the monochromatic continuous wave by a wide margin for multi-derivative systems

Defining a Unified Model of Vocabulary Acquisition via Extensive Reading

Post-secondary students with English as a second language (L2) often struggle with reading their textbooks, and other language-related tasks associated with their coursework, despite achieving the minimum IELTS entry requirement. Much of the difficulty is due to the large difference in the known English vocabulary range of L2 speakers compared to native speakers. Extensive reading, or reading for pleasure, is one method of naturally acquiring vocabulary. However, while past studies into vocabulary acquisition agree that vocabulary is acquired, they disagree greatly about the rate of acquisition with some saying the rate is too low to be useful, especially for academic environments. Many conclusions of these studies were inconsistent due to not applying knowledge of the statistical properties of text. In this project we will test our model based on a meta-study of past research with learners of English so that extensive reading can be appropriately used in future language learning courses