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Hybrid halide perovskites have demonstrated significant efficiency in detecting a broad spectrum of high-energy radiation, including X-rays, gamma rays (γ-rays), and neutrons. Given the common occurrence of mixed radiation fields, we investigated the performance of a perovskite-based detector in a neutron-gamma mixed field. A large methylammonium lead tribromide (MAPbBr3) single crystal (SC) was synthesized via the oriented crystal-crystal intergrowth method. This SC was used to fabricate a gamma detector with carbon electrodes, which was tested in the CROCUS zero-power reactor cavity. The detector’s photocurrent response exhibited a strong correlation with known gamma dose rates, as measured by an ambient Berthold LB 112 gamma probe, facilitating the accurate conversion of photocurrent to dose rate. Notably, the device did not exhibit degradation under neutron radiation exposure. To further assess the impact of neutrons, X-ray diffraction and electron paramagnetic resonance analyses were performed on small MAPbBr3 SCs grown by inverse temperature crystallization. These SCs were irradiated within the CROCUS reactor core and by a Pu-Be neutron source at liquid nitrogen temperature. Our findings indicate that the perovskite material can withstand the nominal in-core operation conditions of the CROCUS reactor. Additionally, it endures irradiation at liquid nitrogen temperature, corresponding to a fast neutron fluence of approximately 1010 cm-2 and a gamma radiation dose of about 50 Gy, confirming only the temporary creation of defects. No signs of long-term deterioration were observed, suggesting a potential self-healing mechanism. This resilience positions perovskite SCs as viable candidates for in-core radiation detection, supporting the further development of miniaturized MAPbBr3 SC devices for such applications.

Exposure to ionizing radiation has been known to affect the mechanical properties of solids; however, the exact mechanisms remain debated. In this study, we test the hypothesis that long lived metastable states formed by trapping of charges within defects influence subcritical cracking (SCC). Crack propagation rates were measured in 5 mol% Yttria‐stabilized zirconia samples, with and without prior exposure to Co‐60 gamma radiation (10 kGy absorbed dose). Crack growth was followed in situ by employing a double cantilever beam specimen inside an environmental scanning electron microscope (ESEM). In comparison with the unirradiated samples, an increased energy release rate of ∼10 J/m2 was required to maintain SCC in the irradiated samples conforming to an increase in SCC fracture resistance. Raman and x‐ray studies preclude any phase transformation and volume change due to irradiation; however, there was a significant change in optical absorption characteristics observed as the darkening of the irradiated sample. Thermally and optically stimulated luminescence measurements suggest that sample darkening is caused by metastable states that form due to charge trapping during radiation exposure. A closer examination of the SEM images demonstrates an increased number of microcracks ahead of the main crack in the irradiated specimens. We conclude that charge trapping in defects due to irradiation, and subsequent detrapping during crack propagation by mechanical stresses, initiate the formation of these microcracks. Consequently, energy is consumed during the interactions between the main crack and the developing microcracks, ultimately ensuing an overall increase in fracture resistance in the SCC regime. [ABSTRACT FROM AUTHOR]

The application of advanced oxidation processes (AOPs) emerged as an interesting topic during the last decade. Many studies have been devoted to the complexity of phenomena imposed by AOPs, and a lot of effort was made to justify the application of AOPs. However, the reliability of AOPs has not been an issue of any extensive work. In this work, failure analysis and comparative reliability study were performed for the chosen AOP system, i.e. a laboratory scale photo- and sonoreactor, during the photocatalytic (UV/TiO2 process) and sonochemical (US/Fenton process) oxidation of model pollutants (dyes and carboxylic acids) in water. Furthermore, a three-criterion analysis approach for the risk assessment was proposed. The set criteria; (i) probability of failure, (ii) estimated cost for the 10 000 working hours and (iii) residual organic content in the system after the applied treatment, resulted in the calculated risk scores, Srisk that enlighten all the crucial aspects of the investigated systems. In conclusion, the analysis was related to the pilot scale reactors. [ABSTRACT FROM AUTHOR]

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Wastewater treatment plant (WWTP) effluents are pointed as hotspots for the introduction of both commensal and pathogenic bacteria as well as their antibiotic resistance genes (ARGs) in receiving water bodies. For the first time, the effect of partially treated submarine effluents was explored at the bottom and surface of the water column to provide a comprehensive overview of the structure of the microbiome and associated AR, and to assess environmental factors leading to their alteration. Seawater samples were collected over a 5-month period from submarine outfalls in central Adriatic Sea, Croatia. 16S rRNA amplicon sequencing was used to establish taxonomic and resistome profiles of the bacterial communities. The community differences observed between the two discharge areas, especially in the abundance of Proteobacteria and Firmicutes , could be due to the origin of wastewaters treated in WWTPs and the limiting environmental conditions such as temperature and nutrients. PICRUSt2 analysis inferred the total content of ARGs in the studied microbiomes and showed the highest abundance of resistance genes encoding multidrug efflux pumps, such as MexAB-OprM, AcrEF-TolC and MdtEF-TolC, followed by the modified peptidoglycan precursors, transporter genes encoding tetracycline, macrolide and phenicol resistance, and the bla operon conferring β-lactam resistance. A number of pathogenic genera introduced by effluents, including Acinetobacter, Arcobacter, Bacteroides, Escherichia-Shigella, Klebsiella, Pseudomonas, and Salmonella , were predicted to account for the majority of efflux pump-driven multidrug resistance, while Acinetobacter, Salmonella, Bacteroides and Pseudomonas were also shown to be the predominant carriers of non-efflux ARGs conferring resistance to most of nine antibiotic classes. Taken together, we evidenced the negative impact of submarine discharges of treated effluents via alteration of physico-chemical characteristics of the water column and enrichment of bacterial community with nonindigenous taxa carrying an arsenal of ARGs, which could contribute to the further propagation of the AR in the natural environment. [ABSTRACT FROM AUTHOR]

Gamma-rays ( γ -rays), wherever present, e.g., in medicine, nuclear environment, or homeland security, due to their strong impact on biological matter, should be closely monitored. There is a need for simple, sensitive γ -ray detectors at affordable prices. Here, it is shown that γ -ray detectors based on crystals of methylammonium lead tribromide (MAPbBr 3 ) ideally meet these requirements. Specifically, the γ -rays incident on a MAPbBr 3 crystal generates photocarriers with a high mobility-lifetime product, allowing radiation detection by photocurrent measurements at room temperatures. Moreover, the MAPbBr 3 crystal-based detectors, equipped with improved carbon electrodes, can operate at low bias (≈1.0 V), hence being suitable for applications in energy-sparse environments, including space. The γ -ray detectors reported herein are exposed to radiation from a  60 Co source at dose rates up to 2.3 Gy h -1  under ambient conditions for over 100 h, without any sign of degradation. The excellent radiation tolerance stems from the intrinsic structural plasticity of the organic-inorganic halide perovskites, which can be attributed to a defect-healing process by fast ion migration at the nanoscale level. The sensitivity of the γ -ray detection upon volume is tested for MAPbBr 3  crystals reaching up to 1000 cm 3 (3.3 kg in weight) grown by a unique crystal growth technique., Competing Interests: The authors declare no conflict of interest., (© 2020 The Authors. Advanced Science published by Wiley‐VCH GmbH.)

We have investigated the optical absorption of metallic and semiconducting carbon nanotubes/CH 3 NH 3 PbI 3 micro- and nanowire composites. Upon visible light illumination semiconducting carbon nanotube based samples show a photo-induced doping, originating from the charge carriers created in the perovskite while this kind of change is absent in the composites containing metallic nanotubes, due to their strikingly different electronic structure. The response in the nanotubes shows, beside a fast diffusion of photo-generated charges, a slow component similar to that observed in pristine CH 3 NH 3 PbI 3 attributed to structural rearrangement, and leading to slight, light induced changes of the optical gap of the perovskite. This charge transfer from the illuminated perovskite confirms that carbon nanotubes (especially semiconducting ones) can form efficient charge-transporting layers in the novel organometallic perovskite based optoelectronic devices.