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Abstract  

Neutron activation laboratories worldwide are at a turning point at which new staff has to be found for the retiring pioneers from the 1960s–1970s. A scientific career in a well-understood technique, often characterized as ‘mature’ may only be attractive to young scientists if still challenges for further improvement and inspiring new applications can be offered. The strengths and weaknesses of neutron activation analysis (NAA) are revisited to identify opportunities for innovation. Position-sensitive detection of elements in large samples, Monte Carlo calculations replacing the use of standards, use of scintillator detectors and new deconvolution techniques for increasing the sensitivity are examples of challenging new roads in NAA. Material science provides challenges for the application of NAA in both bulk samples, ultrathin layers and ultrapure materials.

Open access

Abstract  

The development on neutron activation analysis (NAA) into a technique of practical interest effectively started about 60 years ago, when nuclear reactors became available and widely accessible as intense sources of neutrons. During 50 out these 60 years, the series of Modern Trends in Activation Analysis (MTAA) Conferences acted as a true companion and facilitator of this growth. As trendwatcher they signalized the many initiatives that contributed to the development of activation analysis and its applications. A period has come to an end of impressive development resulting from sometimes revolutionary changes in radiation detection and data processing, and much improved irradiation facilities, NAA has reached a full stage of development, with emphasis on routine application and with remaining developments of in marginal impact. NAA is being challenged increasingly in the last 30 years by alternative techniques for multi trace element analysis. The MTAA Conference and with it the ICAA, the International Committee on Activation Analysis, can play an important and active role in this process of identifying and selecting key areas, and even promoting concerted action in those areas. Such an evolution of focus from retrospective to prospective, from trendwatcher to trendsetter, may well allow the MTAA Conference to continue and even expand its role in future development of NAA and its applications. The ideas about the future of the MTAA Conferences and its organization are elaborated upon and some possible subjects for focused development activities are indicated.

Open access

Abstract  

In order to correct for neutron self-shielding in large-sample prompt gamma NAA, a method has been developed to determine the macroscopic scattering and absorption cross sections, i.e., Σ a and Σ s, using four Cu flux monitors placed around the sample. With Monte Carlo computations, the neutron densities throughout the sample and the resulting and the corresponding self-shielding factor as calculated from the Σ a and Σ s as obtained through the Cu monitors were compared to the true values. The derived Σ a and Σ s were found to be sufficiently accurate as long as Σ t = Σ a + Σ s was less than 0.6 cm−1 and Σ s/Σ t was greater than 0.1.

Open access

Abstract  

New software was developed to assist users of the k 0-approach in NAA to harmonize their results. The k 0-IAEA software uses the holistic approach developed at the Delft Interfaculty Reactor Institute and incorporates the latest k 0 data catalogue together with additional information on coincidence and sum peaks, which together are used in the joint evaluation of samples. Multiple irradiations as well as multiple measurements of samples are treated simultaneously. Flux parameter determination as well as efficiency calibrations of detectors are accommodated using a single-measurement approach as developed at the Interfaculty Reactor Institute, Delft. The standard Windows software will stimulate the application of the k0 approach through the free distribution and updates of the program.

Open access

, Gouriou S , Jallot N , Nordmann P , Naas T : Intrafamilial transmission of extended-spectrum-ß-lactamase-producing Escherichia coli and Salmonella enterica Babelsberg among the families of internationally adopted children . J Antimicrob Chemother

Open access
European Journal of Microbiology and Immunology
Authors: Ali Konaté, René Dembélé, Nathalie K. Guessennd, Fernique Konan Kouadio, Innocent Kouamé Kouadio, Mohamed Baguy Ouattara, Wendpoulomdé A. D. Kaboré, Assèta Kagambèga, Haoua Cissé, Hadiza Bawa Ibrahim, Touwendsida Serge Bagré, Alfred S. Traoré, and Nicolas Barro

Microbiol Infect Dis 70 , 119 – 123 ( 2011 ) 22. Nordmann P , Cuzon G , Naas T : The real threat of Klebsiella pneumoniae carbapenemase

Open access
European Journal of Microbiology and Immunology
Authors: Hans Kollenda, Hagen Frickmann, Rania Ben Helal, Dorothea Franziska Wiemer, Habiba Naija, Mohamed Sélim El Asli, Melanie Egold, Joachim Jakob Bugert, Susann Handrick, Roman Wölfel, Farouk Barguellil, and Mohamed Ben Moussa

-acquired bloodstream infections in a Tunisian pediatric intensive care unit: a 2-year prospective study . Am J Infect Control . 2007 ; 35 : 613 – 8 . 10.1016/j.ajic.2006.09.007 23. Ayari K , Bourouis A , Chihi H , Mahrouki S , Naas T , Belhadj O

Open access

–encoding plasmid in Turkey and beyond . Antimicrob Agents Chemother 2010 ; 54 : 1369 – 73 . 10.1128/AAC.01312-09 5. Cuzon G , Ouanich J , Gondret R , Naas T , Nordmann P . Outbreak of OXA-48–positive carbapenem-resistant Klebsiella

Open access
Orvosi Hetilap
Authors: Róbert Pilisi, Tamás Tényi, András Büki, Norbert Kovács, Antal Zemplényi, Gabriella Sebestyén, Péter Osváth, Sándor Fekete, and Viktor Vörös

-de Lange JJ, Liemburg EJ, Bais L, et al. Effect of bilateral prefrontal rTMS on left prefrontal NAA and Glx levels in schizophrenia patients with predominant negative symptoms: an exploratory study. Brain Stimul. 2017

Open access

Citrobacter obtained in environmental samples of a Tunisian hospital . Diagn Infect Microbiol Dis . 2016 ; 86 : 190 – 3 . 10.1016/j.diagmicrobio.2016.07.013 17. Naas

Open access