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.
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.
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., Σa and Σs, 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 Σa and Σs as obtained through the Cu monitors were compared to the true values. The derived Σa and Σs were found to be sufficiently accurate as long as Σt = Σa + Σs was less than 0.6 cm−1 and Σs/Σt was greater than 0.1.
Authors:M. Rossbach, M. Blaauw, M. Bacchi, and Xilei Lin
New software was developed to assist users of the k0-approach in NAA to harmonize their results. The k0-IAEA software uses the holistic approach developed at the Delft Interfaculty Reactor Institute and incorporates the latest
k0 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.
Authors:Ralf Matthias Hagen, Hagen Hinz, and Hagen Frickmann
, 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
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 )
, Cuzon G , Naas T : The real threat of Klebsiella pneumoniae carbapenemase
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
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