The removal of dyes from industrial wastewater remains a significant environmental challenge. Among the various treatment methods available, adsorption stands out for its simplicity and efficiency. In this study, Mg-substituted hydroxyapatite (xMg-HAp) was synthesized and evaluated for the removal of methyl orange (MO) from aqueous solution. Among the prepared materials, 1.5Mg-HAp exhibited the highest adsorption capacity, reaching 82.74 mg·g-1, with equilibrium achieved within 60 min. The adsorption behavior was best described by the Freundlich isotherm, indicating heterogeneous surface interactions with high affinity toward MO. Kinetic data followed a pseudo-second-order model, suggesting that adsorption is mainly governed by surface interactions. Thermodynamic parameters (ΔG° < 0 and ΔH° > 0) confirmed that the process is spontaneous and endothermic.Mechanism analysis, supported by physicochemical characterization and Hirshfeld surface study, revealed that electrostatic attraction, hydrogen bonding, and weak coordination between MO functional groups and Ca2+/Mg2+ active sites synergistically govern the adsorption process. Mg substitution enhances surface heterogeneity and active site availability, leading to improved adsorption efficiency. These findings demonstrate that 1.5Mg-HAp is a stable and promising adsorbent for dye-contaminated wastewater treatment.

From 18 January to 23 October 2021, 58 paroxysmal events occurred at Mt. Etna volcano by the South East Crater (SEC). Three events, that occurred on 4, 12 March and 24 June, were selected to be studied through a plume dispersion modelling approach. All the selected paroxysms generated ash-SO2 rich plumes ranging from 6 to 8.5 km above the main vent.In this work, we explored the spatial dispersion of the volcanic SO2 plume in each paroxysmal event by using the Weather Research and Forecasting Chemistry (WRF-Chem) model coupled with the time-variable ground-based SO2 flux emission data recorded by FLAME (FLux Automatic MEausurement) scanning spectrometers network managed by INGV-OE (Osservatorio Etneo). In this context, WRF-Chem was specially configured to run with variable Eruption Source Parameters (ESPs), reading at each integration time-step experimentally measured SO2 flux values.The SO2 maps resulting from the WRF-Chem simulations were compared with the dispersion pattern detected by TROPOMI sensor onboard Sentinel-5p satellite, in order to validate the capability of the model in reproducing the volcanic plume dispersion. The comparison for each simulation highlights a very good agreement between simulated data and those observed by the satellite.The ash transport was also modelled in each simulation, considering an ash Mass Eruption Rate (MER) which was inverted from the plume height. The spatial evolution of the ash patterns was compared with data retrieved from the MGS-SEVIRI satellite. The comparison shows a good agreement between simulated and observed maps. Particularly for the 12 March event, the ash comparison clearly shows that the WRF-Chem model was able to well reproduce the eastward path of the ash cloud, even at long distances, as the simulated plume reached Greece about 10 hours after the paroxysm, in agreement with satellite observations.In conclusion, the obtained results testify that the WRF-Chem model can efficiently reproduce the dispersion of both SO2 and ash plume emitted from Mt. Etna volcano over the Mediterranean basin, representing a powerful tool for assessing air quality, flying security and other hazard factors due to volcanic plume transport and deposition from local to Mediterranean scale. In addition, the performed simulations highlighted that the ground-based data measured by the FLAME network play a key role in improving the accuracy in simulating the SO2 dispersion pattern as it allows us to take into account the fluctuating and not stationary nature of volcanic plume emissions.

Preface to the AAPP supplementary issue collecting the proceedings of the international conference on “Atmospheric Monitoring, Modeling, and Simulation” (2–3 December 2019; Messina, Italy).

In recent decades, the effects of climate change and, in particular those caused by global warming, have been increasingly correlated with weather trends. In fact, recent studies have shown that extreme weather events today occur with greater intensity and frequency than in the past. This is discussed in the most recent IPCC AR6 reports. The southern Mediterranean area is increasingly affected by intense meteorological events, such as for example heavy rainfall and heat waves. In recent years (2020 and 2021), two Tropical-Like Cyclone, also defined as Mediterranean Hurricanes – Medicanes, developed in this area. With this regard, the aim of this work is to study through a modelling approach the so-called Apollo Medicane, which affected the Mediterranean Sea in the last days of October 2021. The extreme weather event caused intense rainfall and strong winds in southern Italy,particularly in eastern Sicily. In this context, the simulation was carried out by using the Weather Research and Forecasting (WRF) model in a configuration at 3 km of horizontal resolution, which was specifically optimized for the Sicily region. Finally, the rainfall maps forecasted by WRF model were compared with rainfall accumulations recorded by the Sicilian weather stations. The comparison shows a good agreement between the predicted maps and observed data.

Submarine hydrothermal systems attract increasing interest from the scientific community, as they emit huge amounts of both elements and energy. However, in relation to their extreme environmental conditions (e.g. high temperature and pressure, low Ph) direct measurements can be challenging to perform.In this context, passive hydroacoustics may represent a powerful technique for both short- and long-term monitoring as the typical source mechanisms of the hydrothermal fields, directly related to ascending fluids, radiate sound pressure following different acoustic modes.Here we present preliminary results obtained by using a spectral approach for estimating the gas flow emission rate starting from the acoustic dataset collected between 22nd and 26th August 2022 on a stationary flux vent located at ~1.8 metres depth, inside the shallow hydrothermal field at Baia di Levante in Vulcano island (Aeolian Islands, Italy).To carry out the estimation of the gas flow emission rate emitted by the hydrothermal vent, we implemented a customised inverse modelling algorithm based on a spectral method founded upon the assumption that the acoustic signature of a single bubble event evolves over time as a sinusoid that exponentially decays. According to this approach, we refined the formulation of a forward model for the sound radiated by a stationary, high-flux bubbles’ plume, then the path was backward analysed through the proposed inversion algorithm, which allowed us to obtain the estimated value of the flow emission rate.High-resolution audio frames were recorded by using hydrophones [1 - 12800] Hz, that were deployed in the proximity of the investigated vent, collecting a total amount of 7 bursts of ~10 hour-long each. Preliminary analyses of the Power Spectral Density (PSD) and Pressure Power Spectrum highlighted the presence of different persistent energetic frequency peaks over the environmental background noise coherently with the dynamics of the hydrothermal field. The most energetic ones, likely due to the acoustic signal radiated by a large, resonant bubble plume, consistently confirmed the coupling of the estimated radius with direct observations. The performed analysis allowed us to identify the main features of the vent, characterised by bubbles radii up to 0.03 m that produce the main energetic peak centred at ~100 Hz, along with smaller bubbles generating less energetic peaks up to 2 kHz. Therefore, the algorithm was set to work in a wide frequency range, spanning from 60 Hz to 2060 Hz, in order to estimate all the gas released by the vent.The estimated flow emission rate for the investigated period retrieved values spanning from 3.31 to 6.98 litres per minute, with a mean value of 4.97 litres per minute, in good agreement with the direct observations. These results confirm that passive acoustic methods represent a valid and robust tool for both monitoring and research activity in submarine hydrothermal fields, providing a long-lasting instrument able to detect the fluctuations connected to the variations of such natural systems.

We present a preliminary study on a fast and vesatile approach, based on the use of a portable Raman spectrometer, for the on-site monitoring of the degradation of concrete-based structures by atmospheric and environmental factors. The main results of our investigation evidence that most of the amorphous and crystal materials involved in Carbonation and Sulphate Attack (the main deterioration processes of cement-based materials) can be detected and distinguished with the use of the Raman spectroscopy. The main wave numbers and changes in the relevant chemical phases (CO2−3 , SiO2−4 , SO2−4 etc.) which generally occur under these durability attacks were discussed and summarized. The proposed approach may open new perspectives in the field of structural health monitoring and suggests a powerful instrument to investigate the relevant processes connected with the degradation processes (and the underlying chemical reactions) caused by atmospheric and environmental factors

In this paper we give a detailed mathematical-physical derivation of a limited area meteorological model, used in several applications, describing the motions and the behaviour of the atmosphere, in the troposphere layer, at mesoscale range, modeled as a mixture of compressible, heat conducting, non viscous components. The mixing ratios of water vapor, cloud water, rainwater, ice,… , referred to the dry air density are introduced. We work in a non inertial reference frame, solidal to the rotating Earth, where Coriolis force is neglected, being Rossby number at the considered mesoscale much bigger than 1.We derive the momentum balance equation, the conservation law for the dry air density, the balance equation for the temperature and the balance equations for the densities of the fluid mixture components in two cases: when a local rectangular Cartesian reference frame, called z-system, solidal to the rotating Earth is used and when a new generalized nondimensional η-system is introduced, by means of the hydrostatic pressure. Detailed calculations (with particular assumptions) are worked out, starting from the case where the atmsphere is modeled as a perfect fluid, the dry air.

The selectivity of a novel chemosensor, based on a modified nitrobenzofurazan referred to as NBD-Morph, has been investigated for the detection of heavy metal cations (Co2+, Pb2+, Mg2+, Ag+, Cu2+, Hg2+, Ni2+, and Zn2+). The ligand, 4-morpholino-7-nitrobenzofurazan (NBD-Morph), was characterized using spectroscopic techniques including FT-IR and 1H NMR. Vibrational frequencies obtained from FT-IR and proton NMR (1H) chemical shifts were accurately predicted employing the density functional theory (DFT) at the B3LYP level of theory. Furthermore, an examination of the structural, electronic, and quantum chemical properties was conducted and discussed. DFT calculations were employed to explore the complex formation ability of the NBD-Morph ligand with Co2+, Pb2+, Mg2+, Ag+, Cu2+, Hg2+, Ni2+, and Zn2+ metal cations. The comparison of adsorption energies for all possible conformations reveals that NBD-Morph exhibits sensitivity and selectivity towards metal ions, including Pb2+, Cu2+, Ag+, and Ni2+. However, an assessment of their reactivity using QTAIM topological parameters demonstrated the ligand's greater complexation ability toward Cu2+ or Ni2+ than those formed by Pb2+ or Ag+. Additionally, molecular electrostatic potential (MEP), Hirshfeld surfaces, and their associated 2D-fingerprint plots were applied to a detailed study of the inter-molecular interactions in NBD-Morph-X (X = Pb2+, Cu2+, Ag+, Ni2+) complexes. The electron localization function (ELF) and the localized-orbital locator (LOL) were generated to investigate the charge transfer and donor-acceptor interactions within the complexes. Electrochemical analysis further corroborates the theoretical findings, supporting the prediction of NBD-Morph's sensory ability towards Ni2+ metal cations. In conclusion, NBD-Morph stands out as a promising sensor for Ni2+.

Our current research is focused on designing new corannulene derivatives that exhibit significantly improved photovoltaic characteristics. These improvements comprise reduced excitation energy, a narrower optical band gap, enhanced light absorption capabilities, a high dipole moment, and reduced reorganization energies. Theoretical calculations of these parameters could pave the way for the creation of superior molecules for use in advanced solar cell technologies. In this work, we conducted a computational study (TD-DFT/CAM-B3LYP/ 6-311 +G) to examine the optical and electronic characteristics of a series of short-chain materials derived from a central core-based corannulene (A, B, C, D, and E-systems). The effect of various electron-donor side groups (such as: (1) 4-di(2-thienyl) thieno[3,4][1,2,5]-thiadiazole, (2) 2,2-Methyl Cyclopenta dithiophene, (3) Cyclopenta dithiophene, (4) 3,4-ethylene dioxythiophene, and (5) 4,6-di(2-thienyl)thieno[3,4-c][1,2,5]-thiadiazole (DTTTD)) on the electronic and photovoltaic properties of corannulene derivative as an electron-acceptor (such as radiation lifetime (tau), light harvesting efficiency (LHE), and maximum open circuit voltage (Voc)) was studied computationally. Also, the electron localization function (ELF) and the localized-orbital locator (LOL) analyses are used to discover the electronic localizations and delocalizations that occur after the addition of various ligands. The electronic and photovoltaic properties of each of the designed molecular structures were compared with P3HT as a reference. The obtained results showed that each of the designed molecular structures (especially the D-structure) is very efficient in the field of photovoltaics. Therefore, it seems that the D-structure can act (as a more suitable electron-donor than P3HT) together with phenyl-C61-butyric acid methyl ester (PC61BM) (as a good electron-acceptor) and improve the efficiency of solar cells.

The paper introduces a parametric resonance model for characterizing some features of the brain's electrical activity. This activity is assumed to be a fundamental aspect of brain functionality underpinning functions from basic sensory processing to complex cognitive operations such as memory, reasoning, and emotion. A pivotal element of the proposed parametric model is neuron synchronization which is crucial for generating detectable brain waves. The analysis of the frequency content of brain waves, categorized as delta (0÷4 Hz), theta (4÷7 Hz), alpha (8÷12 Hz), beta (13÷30 Hz), and gamma (30÷100 Hz) reveals, notably, that the mean frequency of each of these brain wave classes is, in sequence, approximately the double of that of the previous one. Based on this observation, the proposed parametric resonance model suggests a cascade of amplification effects. Following the proposed model, in the transition from wakefulness to sleep, the brain wave bands are energized at double frequency by higher frequency neighboring bands; on the contrary, in the sleep to awake transition, brain waves are energized at a half frequency by their lower frequency neighbor waves. Finally, the trend of increasing amplitude values from higher to lower frequencies lends empirical support to the parametric resonant brain model validity.

A novel sensor using gold (Au) doped citrate-hydroxyapatite nanoparticles at different molar ratios wCitHAP-Au (w = 0.2, 0.4, 0.8) was developed. Citrate groups on the HAP nanoparticles surface makes it possible to carry out directly and homogeneously the "one-pot" deposition of the 0.5 % AuNPs from an aqueous solution. wCitHAP0.5Au modified glassy carbon electrodes (GCE) are used in fundamental studies of the electron transfer, and in the construction of sensor devices for the determination of L-Tryptophane (TTP) and L-Tyrosine (TYR). Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) reveal the excellent electrocatalytic activity for oxidation and determination of TTP and TYR into phosphate buffer solution at pH 7 of the 0.2CitHAP-0.5Au/GCE electrode. Linear response ranges under optimal conditions were found to be 3.33 nM to 66.6 mu M for TTP and 6 nM to 66.6 mu M with detection limit of 3.33 nM and 6 nM, respectively. The fabricated sensor shows suitable sensitivity, stability, and can successfully applied for real samples determination. Additionally, Hirshfeld Surface (HS) analysis was conducted to gain deeper insights into the molecular properties, intermolecular interactions, and surface characteristics of the compounds studied. The HS analysis confirmed the presence of intermolecular interactions that stabilize the gold nanoparticles within the hydroxyapatite-citrate matrix, ensuring their uniform distribution and preventing aggregation.

The design and synthesis of molecular nanoswitches using organic molecules represent a crucial research field within molecular electronics. To understand the switching mechanisms, it is essential to investigate various factors, such as charge/energy transfer, electron transfer, nonlinear optical properties (NLO), current-voltage (I-V) curves, Joule-like (LJL) and Peltier-like (LPL) intramolecular phenomenological coefficients, as well as the energy levels of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) boundary orbitals. In this Article, a novel approach to designing a molecular nanoswitch and understanding its ON/OFF mechanism is presented, utilizing the quantum theory of atoms in molecules (QTAIM), density functional theory (DFT), and Landauer theory (LT). These analyses contribute significantly to a deep understanding of switching effects within molecular electronic systems.

Microbial degradation represents an eco-friendly alternative to traditional physicochemical treatments in removing persistent and toxic environmental pollutants, including synthetic dyes (i.e., methylene blue, MB) employed in different industries. The exploitation of thermophilic bacilli, such as those isolated from the shallow hydrothermal vents of the Eolian Islands (Italy), could provide valuable resources for the treatment of warm, dye-containing wastewater. In this study, we evaluated the ability of preformed biofilms on polypropylene perforated balls (BBs) of fifteen thermophilic bacilli, to decolor, degrade, and detoxify MB in aqueous solutions. Among them, BBs of Bacillus licheniformis B3-15 and Bacillus sp. s7s-1 were able to decolorize MB more than 50% in saline solution (NaCl 2%), incubated in static conditions at 45 °C for 48 h. At optimized initial conditions (10 mg L−1 MB, pH 5.2 for B3-15 or pH 4 for s7s-1), the two strains enhanced their decolorization potential, reaching 96% and 67%, respectively. As indicated by ATR-FTIR spectroscopy, the treatment with BB B3-15 was the most efficient in degrading the Cl–C and –NH groups of MB. This degraded solution was 40% less toxic than undegraded MB, and it has no impact on the bioluminescence of Vibrio harveyi, nor the growth of the marine diatom Phaeodactylum tricornutum. Biofilm formed by strain B3-15 on polypropylene perforated balls could be proposed as a component of bioreactors in the treatment of warm, dye-containing wastewater to concomitantly remediate MB pollution and simultaneously counteract harmful effects in aquatic environments.

This study focuses on the experimental thermal response analysis of a newly synthesized nanocomposite, denoted as HAP/PEG, containing Hydroxyapatite-alt-Polyethylene Glycol. Complementary data obtained from density functional theory (DFT) studies afford insights into the structural and optoelectronic properties of the nanocomposite using the 6-31 g (d, p) and LanL2DZ basis sets in gas phase and water. Reduced density gradient used to identify the non -covalent interaction (RDG-NCI). Intermolecular interactions were quantified and analysed using Hirshfeld surface analysis. Topological analysis, including electron localization function (ELF) and localized orbital locator (LOL) maps, reveals non -covalent interactions. The analysis of natural bond orbitals (NBO) provides insights into the nature and strength of chemical bonds within the nanocomposite. We computed significant nonlinear optical (NLO) characteristics, including dipole moment (mu), polarizability (alpha), anisotropy of polarizability (Delta alpha), as well as first and second order hyperpolarizabilities (beta and gamma) using the B3LYP/6-31 g(d, p) method. These results demonstrate that the reported nanocomposite material exhibits a high thermal stability, tuneable optoelectronic properties, and the potential to serve as an excellent second -order NLO material.

The aim of this paper is to describe the phenomenon of oscillators’ synchronization through a didactic experiment that involves a system constituted by a set of weakly coupled oscillating metronomes. A metronome is a device that allows to vary and select the oscillation parameters and to investigate synchronization processes. To carry out the experiment, metronomes were set over a common platform disposed on cylinders arranged transversally and that were free to roll on a fixed plane. In this paper we shall describe a teaching unit addressed to students of an academic course in Physics, Mathematics or Engineering.

The present work aims at exploring the high electrophilic character of 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) toward the morpholine group by an SNAr reaction in acetonitrile or water (thereafter referred to as NBD-Morph). The electron-donating ability of the morpholine causes intra-molecular charge transfer (ICT). In this report, we present a comprehensive study on the optical characteristics using UV-Vis, photoluminescence (cw-PL) and its time-resolved (TR-PL) to determine the properties of the emissive intramolecular charge transfer (ICT) in the NBD-Morph donor-acceptor system. An exhaustive theoretical investigation utilizing the density functional theory (DFT) and its extension TD-DFT methods is an essential complement of experiments to rationalize and understand the molecular structure and related properties. The findings from QTAIM, ELF, and RDG analyses establish that the bonding between morpholine and NBD moieties is of the electrostatic or hydrogen bond type. In addition, the Hirshfeld surfaces have been established to explore the types of interactions. Further, the non-linear optical (NLO) responses of the compound have been examined. The structure-property relationships obtained through the combined experimental and theoretical offer valuable insights for designing efficient NLO material.

One of the objectives of the high school is to support a domain of thought aimed at expanding the phenomenological field so that the experiences can give a greater basic efficacy to the scientific schemes to be adopted. This requires a conceptual change: teachers must guide students towards the awareness that the schemes of spontaneous knowledge and those of scientific knowledge have different contexts of use and this is not easy, also due to the limitations of linguistic tools. From a constructivist perspective, conceptual change mainly concerns the ability to recognize the proper context of a schema and the specific meaning of the words used in the different schemas. A methodological approach that allows us to go in this direction is that of problem-solving, often neglected in Italian secondary schools for various reasons. This contribution, which is placed in the aforementioned perspective, aims to underline the relationship between mathematical language and science. Specifically, through an example of didactic activity - based on problem-solving - it is shown how the study of kinematics can be abstracted into purely mathematical expressions.

The selectivity of novel chemosensor, based on modified nitrobenzofurazan (thereafter, named NBD-Morph), has been investigated for heavy metal cations (Co2+, Pb2+, Mg2+, Ag+, Cu2+, Hg2+, Ni2+, and Zn2+) Detection. The ligand NBD-Morph was characterized through spectroscopic techniques including FT-IR and 1H-NMR. The vibrational frequencies measured in FT-IR and the proton NMR (1H) chemical shifts were accurately predicted employing the density functional theory (DFT) at the B3LYP level of theory. Additionally, the structural, electronic, and quantum chemical properties were studied and discussed. DFT calculations were also carried out to investigate the complex formation ability of the NBD-Morph ligand with Co2+, Pb2+, Mg2+, Ag+, Cu2+, Hg2+, Ni2+ or Zn2+ metal cations. The adsorption energies of all possible conformations are compared and it is deduced that the NBD-Morph is more sensitive to the selected Pb2+, Cu2+, Ag+, and Ni2+ cations. However, the evaluation of their reactivity using QTAIM topological parameters has demonstrated the greater complexation ability of the ligand toward Cu2+ or Ni2+ than those formed by Pb2+ or Ag+. Further, the molecular electrostatic potential (MEP), the Hirshfeld surfaces, and their associated 2D- fingerprint plots were applied for a detailed study of the H-bonding donor-acceptor of NBD---X (X=Pb2+, Cu2+, Ag+ or Ni2+) complexes. The electron localization function (ELF) and the localized-orbital locator (LOL) were generated to investigate the charge transfer and donor-acceptor interactions inside the complexes. The electrochemical analysis supports the theoretical findings for predicting the sensory ability of NBD-Morph towards Ni2+ metal cations. Ultimately, the NBD-Ni2+ is particularly promoted as a good performance sensor.

In this paper, we report the synthesis and characterization of new nanocomposite materials based on hydroxyapatite (HAP) and polyethylene glycol (PEG) with two different ratios (80/20 and 60/20). The structural properties of the synthesized nanocomposite (HAP/PEG) compound based on chemical composition and morphological features of the surface were analyzed using advanced techniques including X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy and scanning electron microscopy-Energy dispersive spectroscopy (SEM-EDS), which all confirmed the formation of the composite. Furthermore, density functional theory (DFT) computational codes are used, in practice, to predict the structural, optoelectronic properties and quantum chemical parameters of the synthesized nanocomposite compounds. Our results revealed that the nanostructured composite materials containing the fragile HAP (with a weak hardness value) and the rigid PEG (with a strong hardness value) led to the development of a novel nanocomposite material exhibiting improved hardness compared to pure HAP. Moreover, the HAP/PEG nanocomposite exhibited a high level of molecular stability.

During the autumn season, Sicily is often affected by severe weather events, such as self-healing storms called V-shaped storms. These phenomena cause significant total rainfall quantities in short time intervals in localized spatial areas. In this framework, this study analyzes the meteorological event recorded on 11–12 November 2019 in Sicily (southern Italy), using the Weather Research and Forecasting (WRF) model with a horizontal spatial grid resolution of 3 km. It is important to note that, in this event, the most significant rainfall accumulations were recorded in eastern Sicily. In particular, the weather station of Linguaglossa North Etna (Catania) recorded a total rainfall of 293.6 mm. The precipitation forecasting provided by the WRF model simulation has been compared with the data recorded by the meteorological stations located in Sicily. In addition, a further simulation was carried out using the Four-Dimensional Data Assimilation (FDDA) technique to improve the model capability in the event reproduction. In this regard, in order to evaluate which approach provides the best performance (with or without FDDA), the Root Mean Square Error (RMSE) and dichotomous indexes (Accuracy, Threat Score, BIAS, Probability of Detection, and False Alarm Rate) were calculated.