Smartphone-based spectrometry system as a prescreening assessment of copper and iron for real time control of water pollution.

Due to anthropogenic actions, the presence of pollutants in water bodies, such as toxic metals, are increasingly negatively affecting water quality, biodiversity and sustainable goals worldwide. Therefore, decentralization of water pollution monitoring with low-cost devices, such as using smartphones, suggests an innovative green technology for in situ and real-time control. In this study, a Handheld Smartphone Spectrophotometry System (HSSS) was developed to estimate copper and iron concentration water samples. The system mainly comprises a portable commercial spectrometer (GoSpectro) that can measure the spectrum of light in the visible region. The HSSS LOD and LOQ for copper were equal to 0.589 and 1.784 mg/L, respectively, and 0.479 and 1.450 mg/L, respectively for iron. In addition, the results of copper and iron concentrations in samples with unknown concentrations using HSSS were close to the Benchtop Spectrophometer (BS). Finally, HSSS performance showed to be a new green technology for water quality management with potential applications for monitoring water resources and also providing further possibilities to measure other pollutants by the same technique, in addition to metals.

Ultraviolet-C Light-emitting Device Against Microorganisms in Beauty Salons.

Background: Ultraviolet light in the UV-C band is also known as germicidal radiation, and it is widely used for decontamination and disinfection of environments, water, and food. The ultraviolet source transfers electromagnetic energy from a mercury arc lamp to an organism's genetic material. When UV radiation penetrates the cell wall of an organism, it destroys the cell's ability to reproduce, through a physical and not chemical process. Thus, the objective of this study was to evaluate the antimicrobial potential of a new UV-C generating device (Asepsis) against clinically important microorganisms that may be present in beauty centers. Methods: We present here a set of tests performed on tools easy to find in beauty salons (hair-brushes, nail pliers, makeup brushes, and, due to the recent COVID-19 pandemic, face mask samples). They were individually contaminated with bacteria (Pseudomonas aeruginosa, Staphylococcus aureus), fungi (Microsporum canis, Trichophyton rubrum, Candida albicans, Malassezia furfur), and the Chikungunya virus. Different times of exposure were evaluated (1, 3, and 5 minutes). Results: There was notable reduction in the microbial load in every test, in comparison with control groups. Best results were observed on face mask samples, while the makeup brush showed less reduction, even with longer periods of exposure. Conclusions: Beauty salons present a risk of infections due to microbial exposure. The device tested can efficiently inactivate, in a short time, microorganisms contaminating most tools found in this setting. The device also showed promising results against enveloped virus.

Nuclear conversion theory: molecular hydrogen in non-magnetic insulators.

The hydrogen conversion patterns on non-magnetic solids sensitively depend upon the degree of singlet/triplet mixing in the intermediates of the catalytic reaction. Three main 'symmetry-breaking' interactions are brought together. In a typical channel, the electron spin-orbit (SO) couplings introduce some magnetic excitations in the non-magnetic solid ground state. The electron spin is exchanged with a molecular one by the electric molecule-solid electron repulsion, mixing the bonding and antibonding states and affecting the molecule rotation. Finally, the magnetic hyperfine contact transfers the electron spin angular momentum to the nuclei. Two families of channels are considered and a simple criterion based on the SO coupling strength is proposed to select the most efficient one. The denoted 'electronic' conversion path involves an emission of excitons that propagate and disintegrate in the bulk. In the other denoted 'nuclear', the excited electron states are transients of a loop, and the electron system returns to its fundamental ground state. The described model enlarges previous studies by extending the electron basis to charge-transfer states and 'continui' of band states, and focuses on the broadening of the antibonding molecular excited state by the solid conduction band that provides efficient tunnelling paths for the hydrogen conversion. After working out the general conversion algebra, the conversion rates of hydrogen on insulating and semiconductor solids are related to a few molecule-solid parameters (gap width, ionization and affinity potentials) and compared with experimental measures.