Building materials of different brands were assessed for the concentrations of 226Ra, 232Th and 40K using HPGe detector. The activity concentrations in the measured samples ranged from 27 ± 8 to 82 ± 8 Bq kg-1 for 226Ra, 41 ± 4 to 101 ± 8 Bq kg-1 for 232Th and 140 ± 8 to 940 ± 19 Bq kg-1 for 40K, respectively. The Radium equivalent (Raeq) activity from the samples was found to be <370 Bq kg-1 as the recommended value for construction materials. This study will set a baseline data for significant standards on radiation exposure of the measured radionuclides in the selected building materials used in Nigeria.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1093/rpd/ncy121 | DOI Listing |
J Chromatogr B Analyt Technol Biomed Life Sci
January 2025
Universite Claude-Bernard Lyon 1, CNRS, CPE-Lyon, CP2M, UMR 5128, Villeurbanne, France. Electronic address:
Carboxylic acids and aromatic compounds are essential building blocks and starting materials for the production of a wide range of fine chemicals and materials. Their recovery from kraft black liquor, an industrial effluent from pulp and paper mills, is a promising way to produce alternative bio-based chemicals. Reliable methods are needed to identify and quantify the molecules of interest in complex mixtures such as black liquors.
View Article and Find Full Text PDFInorg Chem
January 2025
Department of Chemistry, UiT The Arctic University of Norway, N-9037 Tromso̷, Norway.
Building upon an earlier study of heme-nitrosyl complexes (. , , 20496-20505), we examined a wide range of nonheme {FeNO} complexes (the superscript represents the Enemark-Feltham count) and two dinitrosyl iron complexes using DMRG-CASSCF calculations. Analysis of the wave functions in terms of resonance forms with different [π*(NO)] occupancies (where = 0-4 for mononitrosyl complexes) identified the dominant electronic configurations of {FeNO} and {FeNO} complexes as Fe-NO and Fe-NO, respectively, mirroring our previous findings on heme-nitrosyl complexes.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2G2.
Rigid, conjugated molecules are excellent candidates as molecular wires since they can achieve full extension between electrodes while maintaining conjugation. Molecular design can be used to minimize the accessible pi surface and interactions between the bridging wire and the electrode. Polyynes are archetypal molecular wires that feature a rigid molecular framework with a cross-section of a single carbon atom.
View Article and Find Full Text PDFSmall
January 2025
Key Laboratory of Aerospace Materials and Performance (Ministry of Education) School of Materials Science and Engineering, Beihang University, No.37 Xueyuan Road, Beijing, 100191, P. R. China.
A reasonable construction of hollow structures to obtain high-performance absorbers is widely studied, but it is still a challenge to select suitable materials to improve the low-frequency attenuation performance. Here, the FeO@C@NiO nanoprisms with unique tip shapes, asymmetric multi-path hollow cavity, and core-shell heteroepitaxy structure are designed and synthesized based on anisotropy and intrinsic physical characteristics. Impressively, by changing the load of NiO, the composites achieve strong absorption, broadband, low-frequency absorption: the reflection loss of -55.
View Article and Find Full Text PDFSmall
January 2025
Institute of Biomass and Function Materials & National Demonstration Centre for Experimental Light Chemistry Engineering Education, College of Bioresources Chemistry and Materials Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, P. R. China.
As skin bioelectronics advances, hydrogel wearable devices have broadened perspectives in environment sensing and health monitoring. However, their application is severely hampered by poor mechanical and self-healing properties, environmental sensitivity, and limited sensory functions. Herein, inspired by the hierarchical structure and unique cross-linking mechanism of hagfish slime, a self-powered supramolecular hydrogel is hereby reported, featuring high stretchability (>2800% strain), ultrafast autonomous self-healing capabilities (electrical healing time: 0.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!