Developing reading sub-skills: 15 Lesson Plans Adapted from "The Canterbury Tales”for teenagers

Este trabajo enfatiza el uso de la literatura en Clases EFL. La literatura es usada como una técnica para enseñar las cuatro destrezas básicas: lectura, habilidad de escuchar, escritura y la producción oral. Provee herramientas para mejorar vocabulario, pronunciación y estructuras gramaticales. El leer literatura provee beneficios enlistados en este documento. Además, algunas desventajas también son presentadas. La falta de: capacitación de profesores, interés por parte de los estudiantes y material propio de lectura, hacen de la literatura una tarea difícil de completar. Seleccionar el material correcto para una Clase EFL es el aspecto más importante para generar el interés por la lectura en los estudiantes. En este caso los adolescentes son el objetivo de este estudio. “The Canterbury Tales” por Geoffrey Chaucer, es la obra en la cual este proyecto está basado. La obra literaria de Geoffrey Chaucer “The Canterbury Tales” le da al lector la oportunidad de imaginar una cultura diferente, el comportamiento de las personas, sentimientos, diversión y moralejas con las que las personas se identifican. Quince planificaciones de clase adaptadas de “The Canterbury Tales” es la mejor herramienta para cultivar el interés por la lectura. Las más importantes sub-destrezas son mostradas en estas planificaciones. Cada una de estas sub-destrezas demuestra actividades sugeridas que pueden ser practicadas dentro del aula. La incorporación de la lectura en una Clase EFL facilita el trabajo del profesor con estudiantes quienes encontraran en la lectura facilidad y diversión.

Switchable dual-wavelength erbium-doped fibre laser utilizing two-channel fibre Bragg grating fabricated by femtosecond laser

We propose and demonstrate a switchable dual-wavelength erbium-doped fibre ring laser. Competition between the lasing wavelengths in erbium-doped fibre laser at room temperature is suppressed by incorporating a two-channel fibre Bragg grating (TC-FBG), which consists of two highly localized sub-gratings fabricated by femtosecond laser in single mode fibre. Wavelengths and polarization states of the lasing lines are selected by the TC-FBG. Laser output can be switched between single- and dual-wavelength operations by simply adjusting the polarization controller. Stable dual-wavelength output is verified at room temperature with a power fluctuation less than 0.27 dB, and wavelength fluctuation less than 0.004 nm.

Atmospheric calibration for sub-millimeter radio astronomy

This thesis is focused on improving the calibration accuracy of sub-millimeter astronomical observations. The wavelength range covered by observational radio astronomy has been extended to sub-millimeter and far infrared with the advancement of receiver technology in recent years. Sub-millimeter observations carried out with airborne and ground-based telescopes typically suffer from 10% to 90% attenuation of the astronomical source signals by the terrestrial atmosphere. The amount of attenuation can be derived from the measured brightness of the atmospheric emission. In order to do this, the knowledge of the atmospheric temperature and chemical composition, as well as the frequency-dependent optical depth at each place along the line of sight is required. The altitude-dependent air temperature and composition are estimated using a parametrized static atmospheric model, which is described in Chapter 2, because direct measurements are technically and financially infeasible. The frequency dependent optical depth of the atmosphere is computed with a radiative transfer model based on the theories of quantum mechanics and, in addition, some empirical formulae. The choice, application, and improvement of third party radiative transfer models are discussed in Chapter 3. The application of the calibration procedure, which is described in Chapter 4, to the astronomical data observed with the SubMillimeter Array Receiver for Two Frequencies (SMART), and the German REceiver for Astronomy at Terahertz Frequencies (GREAT), is presented in Chapters 5 and 6. The brightnesses of atmospheric emission were fitted consistently to the simultaneous multi-band observation data from GREAT at 1.2 ∼ 1.4 and 1.8 ∼ 1.9 THz with a single set of parameters of the static atmospheric model. On the other hand, the cause of the inconsistency between the model parameters fitted from the 490 and 810 GHz data of SMART is found to be the lack of calibration of the effective cold load temperature. Besides the correctness of atmospheric modeling, the stability of the receiver is also important to achieving optimal calibration accuracy. The stabilities of SMART and GREAT are analyzed with a special calibration procedure, namely the “load calibration". The effects of the drift and fluctuation of the receiver gain and noise temperature on calibration accuracy are discussed in Chapters 5 and 6. Alternative observing strategies are proposed to combat receiver instability. The methods and conclusions presented in this thesis are applicable to the atmospheric calibration of sub-millimeter astronomical observations up to at least 4.7 THz (the H channel frequency of GREAT) for observations carried out from ∼ 4 to 14 km altitude. The procedures for receiver gain calibration and stability test are applicable to other instruments using the same calibration approach as that for SMART and GREAT. The structure of the high performance, modular, and extensible calibration program used and further developed for this thesis work is presented in the Appendix C.