Amir Zacarias Mesquita is Doctor of Science in Chemical Engineering - State University of Campinas/Brazil (2005), Master of Science and Nuclear Technologies - Federal University of Minas Gerais/Brazil (1981) and graduated in Electrical Engineering - Federal University of Minas Gerais/Brazil (1978). He is Titular Researcher and Senior Operator of the IPR-R1 TRIGA nuclear reactor at Nuclear Technology Development Center (CDTN), a research institute of the Brazilian Nuclear Energy Commission (CNEN). Dr. Mesquita is involved in research in nuclear engineering with an emphasis on reactor technology, working mainly on thermo-fluid dynamics and reactor physics. He performs experimental studies on thermal-hydraulic and neutronic of research reactor on topics such as heat transfer, temperature, mass flow, nuclear fuel, power, neutrons flux, reactivity, instrumentation for control of nuclear reactor operational parameters, and data acquisition systems. He is author of more than one hundred technical papers published in international journals and conference proceedings. His research focuses mainly in studies and experiments on alternatives for monitoring the energy released by nuclear fissions, in order to improve reliability and safety of reactors operation. Nominated for The Eni Award 2011 (Azienda Generale Italiana Petroli - AGIP), class: Protection of the Environment Prize. Dr. Mesquita is Coordinator of the Brazilian Project: Theoretical and Experimental Research on Thermal-Hydraulic and Neutronic in Nuclear Research Reactors funded by CDTN/CNEN, the Research Support Foundation of the State of Minas Gerais (FAPEMIG) and Brazilian Council for Scientific and Technological Development (CNPq). He has been collaborating for projects with other research foundations, such as the Federal University of Minas Gerais (UFMG), State University of Campinas (UNICAMP), Coordination for the Improvement of Higher Education Personnel (CAPES), and Research and Projects Financing (FINEP). He is consultant for Ibero-American Development Programme for Science and Technology (CYTED) and the Education Board of Brazilian Nuclear Energy Commission (CNEN). He is expert of the International Atomic Energy Agency (IAEA), member of the Brazilian Association for Nuclear Engineering (ABEN), and professor of Training Course for Operators of Nuclear Reactors at CDTN. He is reviewer of several international conferences and journals such as Annals of Nuclear Energy and Journal of ASTM International. Book Editor: Nuclear Reactors of the InTech Open Access Publisher.