Scientific Program

Conference Series Ltd invites all the participants across the globe to attend International Conference on Nuclear Chemistry San Antonio, Texas, USA.

Day 1 :

OMICS International Nuclear Chemistry 2016 International Conference Keynote Speaker Juan Manuel Navarrete photo
Biography:

Juan Manuel Navarrete is a Researcher Professor in the Faculty of Chemistry, Inorganic and Nuclear Chemistry Department, from the National University of Mexico. He obtained the PhD degree  from Paris VI University, Pierre et Marie Curie, in 1992.He has published about 120 papers and served as arbitrate-in-reputed-scientific-journals.                                                                                                                                                                 

Abstract:

40K radioactive detection in foodstuff is easily performed by filling Marinelli containers with any food sample in order to detect the γ rays emitted (energy 1461 KeV, 11% decaying  nucleus to 40Ar by electron capture, EC), and detectd either by one NaI(Tl) scintillation or HPGe semiconductor detector. So, if each one is used during a suitable detection  time, for example 12 hours overnigth, counts number with reasonable standard deviation are accumulated, and it is possible to compare and obtain better results, when Bq per gram of sample (Bq/gs) is divided by specific activity of elementary K (31.19 Bq/gK) and multiplied by 100, to get the K concentration  in the sample as percentage. In this way, to obtain Bq/gs next equation is used:

Bq/gs = Cs – Cb/Ws.xDet. Eff.x0.11 (where: Cs=counts per second obtained from sample;Cb=counts per second  obtained from background; Ws=foodstuff sample weigth in grams;Det. Eff.=Detection Efficiency of each detector for 1461 KeV γ rays/100; 0.11=40K branching ratio decaying to 40Ar  by EC). Elementary K  specific activity is a constant obtained from next equation:

Bq/gK = λN = 0.693x6.02x1023x0.0118/1.28x109x365x24x3600x39.1x100=31.19 Bq/gK

(where: λ=40K decay constant; N=40K atoms number per K gram; 0.693=ln 2; 6.02x1023= Avogadro’s number; 0.0118/100=40K isotopic abundance;1.28x109x365x24x3600=40K  half life in seconds; 39.1=Elementary K atomic weigth).

And finally:

              K(o/o)=Bqx100/gs  /  Bq/gK  = gKx100/gs

So, severalvegetables, seeds and grains have been analysed for K concentration, and this paper presents the higher K concentration in  peels, related to grains of cacao and coffee, obtained by this non destructive, easy and precise enough procedure.     

OMICS International Nuclear Chemistry 2016 International Conference Keynote Speaker Diane Lebeau photo
Biography:

Diane LEBEAU has completed her PhD from UPMC University (Paris, France) and postdoctoral studies from Roche Diagnostics laboratories in Germany. She is research engineer in the Laboratory of Radiolysis and Organic Matter (LRMO) at the French Alternative Energies and Atomic Energy Commission (CEA, France) since 2009. As a specialist in analytical chemistry, she contributes to the research program conducted by the CEA and devoted to small organic molecules and polymer degradation in the nuclear context. She has published 10 papers.

Abstract:

Because of the wide range of formulations, one class of polymer can have different composition (nature of the monomer, quantity and concentration of monomers for copolymers, average molar mass and so on). Their additives can also be adjusted. In the area of polymers analysis, one of the most important interest is to develop analytical methods allowing a fast and complete characterization of its chemical structure. In the very special context of the nuclear industry, and more specially in the nuclear waste safety domain, degradation mechanisms of polymers have to be understood up to doses as high as dozen of MGy. At theses doses, materials are highly modified, depending on the polymer kind and on the additives. The first in the understanding of the mechanisms is to characterize materials at different doses.

Mass spectrometry allows today to analyze molecules directly from sample for rapid analysis, without any sample preparation. In this study, two ionization sources have been used, Atmospheric Solid Probe Analysis (ASAP) and Direct Analysis in Real Time (DART), for characterization of two industrial polymers, polyurethanes and polyethylene.

DART technique allows detection of additives with good intensity, whereas ASAP technique allows a better desorption of high molar mass polymers in function of their volatilization and/or degradation temperature. Thus, these results compare and contrast these two complementary thermal-based ionization techniques for the direct study of crude polymer. In the nuclear context, these two sources allow to help to follow and understand chemical modification of the polymer with dose.