PRINCIPAL COMPONENT ANALYSIS (PCA) FOR CHEMICAL DATA EVALUATION AND HEAT MAPS PREPARATION: A TUTORIAL. This tutorial shows a step-by-step guide on handling big datasets using principal component analysis (PCA). A dataset of chemical elements’ concentration, emission spectrum, and energy-dispersive X-ray fluorescence (EDXRF) of e-waste were used as examples. Five routines were proposed to apply data processing and PCA calculation focusing data from laser-induced breakdown spectroscopy (LIBS), EDXRF, and heat maps preparation. These routines can be used in various softwares such as MatLab, Octave, R, and Python. PCA was applied in three examples; the first was for concentrations, and the other two were for spectra. An example of heat maps assembling a hyperspectral image of a printed circuit was also described. In addition, a playlist was created on YouTube using the available examples. Therefore, with this tutorial, it may be possible to learn how to deal with a large volume of data by applying PCA. The authors hope to contribute to those researching in the area. (PCA PREPARATION TUTORIAL stepbystep step . elements concentration spectrum energydispersive energy dispersive Xray X ray EDXRF (EDXRF ewaste e waste examples laserinduced laser induced LIBS, LIBS , (LIBS) preparation MatLab Octave R Python concentrations spectra described addition Therefore area (LIBS

This tutorial intends to show to the readers a step-by-step guide to perform a factorial design in their experiments. The examples used here cover most of doubts and questions related to teaching classes at graduation course. Free computational software was applied, as well as, codes were designed by the authors for the calculations. The complexity of each example is attached to the challenges and decisions that the experimentalist faces in its research. In addition, 24 videos were prepared to help the readers. The authors hope to foster the factorial design as an easy and helpful tool for chemists and general researchers in academia and industry.

The first days of radioactivity, the discoveries of X-rays, radioactivity, of alpha- and beta- particles and gamma- radiation, of new radioactive elements, of artificial radioactivity, the neutron and positron and nuclear fission are reviewed as well as several adverse historical marks, such as the Manhattan project and some nuclear and radiological accidents. Nuclear energy generation in Brazil and the world, as an alternative to minimize environmental problems, is discussed, as are the medicinal, industrial and food applications of ionizing radiation. The text leads the reader to reflect on the subject and to consider its various aspects with scientific and technological maturity.