Articles — Recent

As LED systems have been evolving today in a great number of niche applications including automotive lighting, water purification, and skin imaging etc., extensive studies of scientists and engineers in the field have been constantly looking for ways to reduce generated heat loads and maximize the light output to reach the highest efficiency ratios. While the current systems developed over the last years achieved to reach even a 40% LED light efficiency, a higher portion of the electrical input energy of LEDs is still produced as heat and it hinders their development potential. In addition, the compact size of the LED systems poses some challenges to the reliable characterization of their performance at low uncertainties. Especially, the performance considerations associated with thermal loads over a limited size of LED chips require the effective characterization of these systems for various operational conditions. One of the techniques used for this purpose is that an LED package is characterized by a decrease in forward voltage with increasing junction temperature. As LEDs are operated at higher junction temperatures, the amount and quality of the light deteriorates significantly, and the less efficient use of the LEDs results in additional operating costs and reduced lifetime of LEDs. In fact, accurate identification of thermal behavior of LED packages is one of the essential tasks towards improving the design of LED systems. If thermal characterization of LEDs is accurately done, performance parameters of LED packages are more reliably optimized to yield the highest possible performance ratios. Thus, this study focused on the design and manufacturing of a thermally improved and fully operational rapid temperature controllable chamber in which calibration and test phases of junction temperature measurements are sensitively conducted under a low uncertainty.

In this paper novel approaches to optical beam shaping for lighting systems are presented. Application of various computer generated micro/nano-structured optical components is discussed.

NBD-NIR report

Kgomotso Julian Sebitlo's CV. Created with the AltaCV template.

En este ensayo se expondr aspectos de la minera de datos orientada a la ingeniera, y como durante el tiempo su uso nos ha beneficiado de manera conveniente, volviendo tareas tediosas y complejas, algo fcil y casi automatizada, un proceso que se fue adaptando conforme se iban requiriendo nuevas tecnologas ya que cada vez van surgiendo datos ms complejos y una forma que pudiera interpretar este tipo de datos, algo que le exigi evolucionar junto con este tipo de datos y adaptarse al da a da, volvindose algo casi fundamental para todo tipo de empresas que interactan con grandes cantidades de datos requieren emplear de la minera de datos, ya que de la manera antigua quizs no logren objetivos tan eficaces y de manera rpida, pasando de un proceso desconocido a algo que la mayora de empresas emplean actualmente, actualmente es un proceso que va de la mano con prcticas como la analtica, un proceso que las empresas que requieren saber de qu es eficaz y que no, tienen que hacer uso de estos si o si.

Master's thesis at the Moscow State University: Effect of tensor interactions at beta decay and capture speed electrons with heated nuclei

Provides an Extensive Guide to LaTeX along with the source code. This provides a template for documentation.

Bert de Vries's CV

Aymen Kefi's CV. Created with the USA STEM CV template.