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In what area, specifically, were your post graduation studies concentrated? Why did you choose this area? The topic of my Ph.D. thesis was conceived and written completely on my own, I chose a very unusual combination of linguistics, statistics (power-law distributions) and statistical physics. This was viewed as strange but I thought was far more interesting than the conventional topics that my teachers mentioned as possibilities. The thesis was very badly written, but much of its content has survived and is now viewed as "classical".

Biodiesel, a biodegradable renewable product that obeys the carbon cycle, comes detaching more each time in the national scene due to the National Program of Production and Use of Biodiesel from the Federal Government, that stipulates a 2% obligatory addition of biodiesel to the Diesel oil starting at 2008. However the possibility of massive production of biodiesel in Brazil represents a serious threat to the drinking water sources, since one of the critical stages that guarantee the fuel quality is the laudering with water to the removal of biodiesel's by-products, such as the glycerin, the residual alcohol and the catalyst that still mixed in the renewable fuel. This water enters in the process of production not contaminated (some times also potable) and returns to the environment contaminated, presenting pH = 11, oils and greases near of 500 mg L-1, color equal to 3,000 mg L-1, turbidity equal to 905 NTU, beyond a chemical demand of oxygen equal to 16,564 mg L-1. This values are in disagreement with the Conama Resolution nº357. However after treatment it obtains pH = 6, nothing detected for oils and greases and color, 0,64 NTU for turbidity and chemical demand of oxygen equal to 5,000 mg L-1.

This work was carried out as an exercise in developing open source software to interface with free hardware. In this work a software was developed to perform serial communication between a computer (PC) and the Arduino, aiming at the simultaneous recording of two temperatures measured by type K thermocouples as a function of time. The temperatures measured by the analog instruments, thermocouples type K, were converted into digital signals through the MAX6675 and sent to the PC via the Arduino serial port. At the computer these data were expressed graphically in real time through the application developed for this purpose and then stored in files compatible with spreadsheets for subsequent mathematical analysis.

After almost 20 years working with scientific publications, this is the first time I am not sure how to proceed. However, I will try to do an excellent special Issue about Professor Lavinel. If you are wondering why this edition is late, the answer is simple. It is because I am stubborn, and I learned from the best about how to be stubborn. Also, it is not so fun to work in Professor’s Lavinel Journal without him. In fact, it is very hard. I start to work with Professor Lavinel around 2002 or 2003, I was a student of his in the classes of wave-mechanics or quantum chemistry, as he used to say. Until that time, the graduation course in Chemistry was not so interesting to me, but the classes were so impressive that when I was approved, I made to Professor Lavinel the most awkward request “next semester can I retake this course?”. I remember the expression in his face, and he said: “you were approved, why to retake this class?”. My answer was not the best, but in the end, he allowed me to see the classes again. So during the next semester, there was I, in every class paying attention. The support of my friends and family was exceptional. The phrases “are you crazy?” and “this is a hard class why are you taking it twice?”. But as Goldani used to say “your criticism only makes me stronger.”. In the end, there was I learning how to make new things. At that time it used to make sense to me, and chemistry becomes much more straightforward.