We lost our dear friend Ömer Gönül, who started to work as a Training and Research Assistant at HIDRO in 2014, on 20 April 2018 due to his illness. He started his undergraduate education with a full scholarship in the Department of Mechanical Engineering at our university in 2009 and graduated with high achievements and made important contributions by taking part in the establishment of HIDRO. We would like to thank and express our gratitude to her precious mother, Hatice Gönül, and her father, Sabahattin Gönül, for raising such a beautiful person full of kindness, for their efforts in the education of our friend, who has been successful throughout her education life, and for giving us the opportunity to work with such a valuable person. We will always carry the memory of our dear friend in our hearts.