LaMnO3 (LMO) nanoparticles were synthesized using the reverse micelle route and thoroughly characterized to determine their structural, morphological, optical, electrical, and magnetic properties. The single-phase formation of a cubic deformed perovskite structure with good crystallinity was confirmed by X-ray diffraction (XRD) and Rietveld refinement. Irregularly shaped nanoparticle agglomeration with a porous morphology was observed by scanning electron microscopy (SEM), and a homogeneous elemental distribution and phase purity were confirmed through energy-dispersive X-ray spectroscopy (EDS). Fourier-transform infrared (FTIR) spectroscopy complemented the characteristic Mn-O vibrational modes, allowing the stabilization of the well-defined MnO6 octahedra. UV-visible spectroscopy indicated a direct optical bandgap of approximately 1.96 eV, suggesting its potential for use in visible-light-driven electronics. Electrical resistivity measurements exhibited thermally activated behavior with an activation energy of 0.21 eV, which is compatible with small polaron hopping in perovskite oxide semiconductors. Magnetic measurements at room temperature revealed that the size-induced surface effects and oxygen vacancies caused weak ferromagnetism.

Photocatalytic-photothermal evaporators are emerging as promising water purification technologies capable of removing both inorganic and organic pollutants while offering low-cost and low-energy desalination. Despite their potential, the interplay between photocatalysis and photothermal evaporation remains poorly understood. Here, we investigate the sequential application of the two processes and demonstrate, for the first time, the existence of synergistic effects that are independent of the specific materials used. We show that pollutant rejection by evaporation is very effective on the aromatic intermediates formed via hydroxyl-radical attack - an insight of general relevance to advanced oxidation processes. However, we also identify p-benzoquinone as a critical volatile intermediate whose concentration remains significant in the distillate after conventional liquidphase photocatalysis combined with evaporation. By examining the role of the water matrix, including common inorganic electrolytes and non-volatile organic compounds, we further reveal conditions under which the combined process becomes practically ineffective - an issue not previously recognized for photocatalytic-photothermal systems. Building on these findings, we propose an improved treatment sequence in which the evaporation step is brought forward, mitigating the inhibitory effects of non-volatile species and enabling robust synergistic coupling. This work highlights the overlooked importance of gas-phase photocatalysis and provides a rational framework for the future design and optimization of photocatalyticphotothermal evaporators.

The use of cylindrical solar panels, designed to power electric pole-mounted devices, offers notable advantages, such as always presenting a side towards the sun and a heightened sensitivity to the diffuse component of solar radiation. A central pole quad array configuration can significantly enhance energy output but introduces the issue of minimizing the distance from the pole to avoid complex structural engineering.This study introduces a model to predict the power output of a central pole quad array based on its geometric parameters, such as the distance between the cylindrical panels and the central pole and the array’s azimuthal orientation. The model incorporates environmental data and distinguishes between direct and diffuse solar radiation components. Additionally, it accounts for the mutual shading effects among panels, enabling the generation of a power output profile over time and providing an estimate of the daily energy output.The model is then applied to evaluate the energy performance of the system as a function of the distance between the pole and panels and the array’s azimuthal orientation. Results indicate that the azimuthal orientation has a significant impact on the system’s energy yield, with variations of up to 10% achievable by simply adjusting the installation angle. Furthermore, it was found that the optimal azimuthal angle is not fixed but depends on the chosen pole-to-panel distance.

The optical properties of quantum dots (QDs) can be altered by employing surface plasmon metallic nanoparticles close to the QDs. In this study, we investigate the photoluminescence (PL) enhancement of CdSe/CdS core-shell QDs coupled with gold nanoparticles (AuNPs) due to the plasmonic effect. The effect of the morphology of AuNPs and the importance of the spacer layer were also analyzed. The AuNPs are deposited on a glass substrate by magnetron sputtering to achieve precise morphological control. The deposited nanoparticles have a uniform distribution and optimal particle size ranging between 10 and 12 nm. A poly-(methyl methacrylate) (PMMA) spacer layer was employed between QDs and AuNPs to control the separation and avoid quenching effects due to Förster resonance energy transfer (FRET). Maximum PL enhancement was observed for a spacer layer of 25 nm thickness due to the plasmonic effect. This coupled structure can potentially be used to enhance the PL of QDs acting as a downshifting layer, which can be used to improve the power conversion efficiency (PCE) and improve light trapping in solar cells.

Flexibility, light weight, and mechanical robustness are the key advantages of flexible photovoltaic (PV) modules, making them highly versatile for sustainable energy solutions. Unlike traditional rigid PV modules, their flexible nature makes them incredibly versatile for harnessing energy in places where doing so was once impossible. They have a wide range of applications due to their flexibility and moldability, making it possible to conform these modules to surfaces like curved rooftops and other irregular structures. In this paper, we provide a comprehensive review of all the materials used in flexible PV modules with a focus on their role in sustainability. We thoroughly discuss the active-layer materials for crystalline silicon (c-Si)-based solar cells (SC) and thin-film solar cells such as cadmium telluride (CdTe), as well as copper indium gallium diselenide (CIGS), amorphous thin-film silicon (a-Si), perovskite and organic solar cells. Various properties, such as the optical, barrier, thermal, and mechanical properties of different substrate materials, are reviewed. Transport layers and conductive electrode materials are discussed with a focus on emerging trends and contributions to sustainable PV technology. Various fabrication techniques involved in making flexible PV modules, along with advantages, disadvantages, and future trends, are highlighted in the paper. The commercialization of flexible PV is also discussed, which is a crucial milestone in advancing and adapting new technologies in the PV industry with a focus on contributing toward sustainability.

The surface ligands in colloidal metal halide perovskites influence not only their intrinsic optoelectronic properties but also their interaction with other materials and molecules. Donor–acceptor interactions of CsPbBr3 perovskite nanocrystals with TiO2 nanoparticles and nanotubes are explored by replacing long‐chain oleylamine ligands with short‐chain butylamines. Through postsynthesis ligand exchange, the nanocrystals are functionalized with butylamine ligands while their intrinsic properties are maintained. In solution, butylamine‐capped nanocrystals exhibit reduced photoluminescence intensity with increasing TiO2 concentration but without any change in photoluminescence lifetime. Intriguingly, the Stern–Volmer plot depicts different slopes at low and high TiO2 concentrations, suggesting donor‐acceptor interaction through mixed static photoluminescence quenching and quenching sphere of action mechanism . Oleylamine‐capped nanocrystals in solution, on the other hand, show no interaction with TiO2, as indicated by consistent photoluminescence intensities and lifetimes before and after TiO2 addition. In films, both types exhibit decreased photoluminescence lifetime with TiO2, indicating enhanced donor–acceptor interaction, which is discussed in terms of electron transfer. TiO2 nanotubes enhance nonradiative recombination more in butylamine‐capped CsPbBr3 perovskite nanocrystals, emphasizing the role of ligand chain length.

This study investigates the influence of three critical 3D-printing parameters-layer height, print speed, and extrusion temperature-on the mechanical properties of liquid crystalline polymer 3D-printed specimens, using a low-end 3D-printer. The extrusion process during 3D-printing can further align the molecular domains within the material along a common direction, leading to a reinforced polymer structure with superior properties. Specifically, the tensile strength, deformation at rupture, and flexural elastic modulus were evaluated to determine how layer height, print speed, and extrusion temperature affect the structural integrity of the printed components. The results demonstrate a significant improvement in both tensile strength and flexural modulus with the reduction of layer height from 0.16 to 0.08 mm. The study highlights the challenges associated with interlayer adhesion in liquid crystalline polymers 3D-printing, which is crucial for optimizing the mechanical performance of printed parts. Post-processing annealing was conducted over a wide temperature range (100 degrees C-250 degrees C), revealing its potential to further enhance material strength, though molecular diffusion emerged as a limiting factor in its effectiveness. By successfully demonstrating these advancements with a low-end 3D printer, this research paves the way for wider adoption of liquid crystalline polymers in additive manufacturing. The use of accessible and cost-effective equipment ensures that these high-performance materials can be integrated into diverse applications, promoting democratization of advanced polymer technologies.

The interest in titanium and its oxides keeps growing on account of their peculiar engineered properties, which find applications in several fields, from architecture to bioengineering, from automotive to photovoltaic cells and photocatalytic devices. There are several methods that allow to grow titanium oxides, among which anodic oxidation has the nice advantage of growing TiO2 nanostructures directly immobilized on a substrate, avoiding the issue of nanostructure recovery from the medium [1]. Yet, these systems also present a drawback, i.e., the immobilization on a metallic, non-transparente and non-permeable substrate. For this reason, different methods have been developed to detach the nanotubes layer and use it as a self-standing membrane [2]. In this work, we address this specific challenge and present the obtaining and characterization of self-standing TiO2 nanotubes membranes. The application envisioned requires their mandatory detachment, as the membranes will be used inside a solar evaporator device to improve the quality of evaporating water, by removing also volatile compounds that may evaporate together with water, reducing the purification extent. Membranes are produced by anodizing commercially pure titanium sheets in ethylene glycol solutions containing different amounts of water, ammonium fluoride and lactic acid. Anodizing time was varied between 30 min and 90 min, and voltage was varied between 30 V and 60 V. Double anodizing was performed to ensure better nanotubes uniformity; then annealing was performed at 500°C for 2 h to allow for oxide crystallization to anatase form. Afterwards, a third, brief anodizing step (10 min) was needed to facilitate nanotubes detachment, which then was carried out chemically, by immersion in HCl. An example of SEM image of detached membrane is shown in Figure 1, indicating that membranes can indeed be obtained and have sufficient mechanical stability to allow for handling and testing. SEM and XRD results indicate a thickness ranging from few micrometers to tens of micrometers, and their crystal structure is mainly anatase, although small quantities of rutile may form in the base of the oxide. Preliminary photocatalysis tests were conducted on the degradation of organic dyes, showing promising photoactivity. Several decoration methods were also considered, with different aims: silver nanoparticles for antifouling, and quantum dots for improved photoactivity. Silver nanoparticles did not enhance photoactivity, and in some cases decreased it slightly; yet, their scope was different, i.e., exploiting the antibacterial and antifouling characteristics of silver on the membrane layer, therefore the formulation leading to unaltered photocatalytic activity was selected for the prosecution of this work, which envisions antibacterial and antifouling testing procedures. Acknowledgements: We acknowledge financial support under the National Recovery and Resilience Plan (NRRP), Mission 4, Component 2, Investment 1.1, Call for tender No. 1409 published on 14.9.2022 by the Italian Ministry of University and Research (MUR), funded by the European Union – NextGenerationEU– Project Title COPE - COmposite nanomaterials coupling Photothermal Evaporation and photocatalysis for durable water purification systems – CUP G53D23006660001 - Grant Assignment Decree No. 1384 adopted on 01.09.2023 by the Italian Ministry of Ministry of University and Research (MUR). References Lee, K.; Mazare, A.; Schmuki, P. (2014) One-dimensional titanium dioxide nanomaterials: Nanotubes. Chem. Rev., 114, 9385–9454. So, S.; Hwang, I.; Riboni, F.; Yoo, J.; Schmuki, P. (2016) Robust free standing flow-through TiO2 nanotube membranes of pure anatase. Electrochem. Commun., 71, 73–78. Figure 1: Morphology of nanotubular membrane. Figure 1

The use of single-use or disposable plastic objects has massively increased during the last few decades, and plastic has become the main type of litter found in marine environments. The Adriatic Sea is seriously prone to marine litter pollution, and it collects about one-third of all the freshwater flowing into the Mediterranean, mainly via the river Po. This study investigated the type and composition of large microplastic debris collected in different sites in the Po Delta area. Visual classification was performed by relevant criteria, while chemical composition was assessed by infrared spectroscopy. The main plastic fraction is composed of polyolefin (76%), followed by polystyrene (19%). This proportion roughly matches global plastic production, rescaled after excluding plastics with negative buoyancy: all the identified compounds have a specific gravity lower than that of the seawater. Fragments (irregularly shaped debris) represent the most abundant category fraction (85%), followed by pellets, which represent roughly 10% of the total. Overall, the results provided an insight into large microplastic pollution in beach sediments in the Po delta area.

(1) Background: Self-adhesive systems have been proposed for the orthodontic bonding with the intention to reduce the traditional three-component system. (2) Methods: The sample consisted of 32 extracted intact permanent premolars randomly divided into two groups (n = 16). In Group I the metal brackets were bonded with Transbond XT Primer and Transbond XT Paste. In Group II the metal brackets were bonded with GC Ortho connect. The resin was polymerized for 20 s from two directions (mesial and occlusal) using a Bluephase light-curing unit. The shear bond strength (SBS) was measured using a universal testing machine. Immediately after SBS testing, Raman microspectrometry was performed for each sample to calculate the degree of conversion (DC). (3) Results: There was no statistically significant difference in the SBS between the two groups. A significantly higher DC (p < 0.001) value was recorded in Group II, in which the brackets were bonded with GC. Very weak or no correlation (0.01) was recorded between SBS and DC in Group I and moderate positive correlation was recorded in Group II (0.33). (4) Conclusions: No difference was found in SBS between the conventional and two-step systems used in orthodontics. The two-step system demonstrated higher DC compared to the conventional system. There is a very weak or moderate correlation between DC and SBS.

This paper proposes an energy management system (EMS) for a photovoltaic (PV) grid-connected charging station with a battery energy storage system (BESS). The main objective of this EMS is to manage the energy delivered to the electric vehicle (EV), considering the price and CO2 emissions due to the grid’s connection. Thus, we present a multi-objective two-stage optimization to reduce the impact of the charging station on the environment, as well as the costs. The first stage of the optimization provides an energy schedule, taking into account the PV forecast, the hourly grid’s CO2 emissions factor, the electricity price, and the initial state of charge of the BESS. The output from this first stage corresponds to the maximum power permitted to be delivered to the EV by the grid. Then, the second stage of the optimization is based on model predictive control that looks to manage the energy flow from the grid, the PV, and the BESS. The proposed EMS is validated using an actual PV/BESS charging station located at the University of Trieste, Italy. Then, this paper presents an analysis of the performance of the charging station under the new EMS considering three main aspects, economic, environmental, and energy, for one month of data. The results show that due to the proposed optimization, the new energy profile guarantees a reduction of 32% in emissions and 29% in energy costs.

The fabrication of poly(oxymethylene) by means of additive manufacturing is still a problematic procedure due to the low adhesion with standard printing plates and extended warping. The use of polymers as alternative substrates is an effective way, especially if their glass-transition temperature is below the processing temperatures. Using poly(methyl methacrylate) sheets as sacrificial substrate, standard samples of poly(oxymethylene) are successfully printed, a result achieved in the past only by means of expensive and complex equipment. Furthermore, the mechanical and thermal properties of poly(oxymethylene) upon UV aging up to 500 h are investigated. Our results demonstrate that aging of 3D-printed poly(oxymethylene) causes chain scission and weakening of intermolecular bonds, crystallization of part of the amorphous areas, and results in the embrittlement of the material. The intermolecular structure of poly(oxymethylene) has been investigated by means of Fourier transform infrared spectroscopy.

A thermodynamic model based on a modified Classical Nucleation Theory is applied to the formation of colloidal metal and semiconductor nanocrystals. The predictions of the model are compared to experimental results published in the literature and well-established kinetic models, indicating an overall good accuracy. The definition of a potential energy curve that characterizes the system allows the prediction of the final (equilibrium) size of crystals as well as their size distribution. Furthermore, the nucleation process is studied in terms of key parameters affecting the concentration of crystals and is found to be related to the change in critical energy of stable nuclei during nucleation. Threshold values for the nuclei concentrations are predicted, defining instability and metastability conditions for the nucleation process. This model can help in refining our understanding of the mechanisms behind nucleation and growth of nanocrystals, with the goal of optimizing the fabrication process for industrial-scale production of nanocrystals and nanocrystal-based devices.

We analysed the major, minor and trace elements chemistry of forty-two Cr-spinels from four Siberian kimberlites. They showed a wide range in Mg# (Mg/(Mg + Fe2+); 0.42–0.78) and Cr# (Cr/(Cr + Al); 0.32–0.92) and a common trend of increasing Cr# with decreasing Mg#. The major element classification schemes suggested that there were spinels deriving from a peridotitic source (Xen) and spinels crystallised from kimberlitic melts (Chr). Laser-Ablation Inductively Coupled Plasma Mass Spectrometry on both groups showed that the trace elements with the highest abundance were Mn (985–3390 ppm), Ni (531–3162 ppm), V (694–2510 ppm) and Zn (475–2230 ppm). Testing the effectiveness of trace elements in determining the source for Cr-spinels, we found out that Cr-spinels crystallised directly from a kimberlitic melt usually showed higher Mn, Ni, Sc and V concentrations with respect to those of peridotitic origin. In addition, using the available partitioning models, we found that the correlations between major elements and Ni, Co, Sc and Ga in the Xen group could be explained by subsolidus equilibration between spinel, olivine and clinopyroxene at 800–1000 °C, thus supporting a peridotitic source for this group. Finally, we calculated the composition of the possible melts in equilibrium with the Cr-spinels of the Chr group, using a selected set of partition coefficients. Calculated abundances of Cu, Ga and Zr were comparable to those of the kimberlite, while V was never close to the kimberlite composition. This simulation highlighted the need for new data on the trace elements partition coefficients between kimberlitic melts and Cr-spinel.

Upconversion is the process based on the transformation of incoming low energy photons to higher energy emitted radiation. Upconverting materials are exploited in several novel applications like biolabeling and radiation harvesting, among others. Thanks to their intrinsic potential, it is very important to be able to fabricate functional devices based on such materials, and to do so in a controllable and affordable way. We investigated the below-bandgap stimulated radiation of heterostructures, obtained from core–shell semiconductor quantum dots, for the development of a large area upconverting system. The upconversion photoluminescence, after sintering of the nanoparticles, has been measured and the conversion mechanism investigated. The presence of intermediate states within the bandgap of the structure, derived from the specific quasi type-II configuration of the core–shell quantum dots, activated a uniform single photon upconversion mechanism on a wide surface area of the developed films, resulting in an anti-Stokes shift larger than 0.4 eV.

The increasing number of commercial, technological and scientific missions for CubeSats poses several concerns about the topic of space junk and debris mitigation. As no regulation is currently in place, innovative solutions are needed to mitigate the impact that Low Earth Orbit objects can have during uncontrolled re-entry and the associated potential events of surface collision. We investigated the requirements, in terms of materials selection, for the development of a 3D-printed structural bus able to withstand loads during launch and in-orbit operations, with the objectives to be as light as possible and requiring the least amount of heat for demise during atmospheric re-entry. The selection indicated magnesium alloys as the best candidates to improve the reference material, aluminium 6061 T6, resulting in both mass-reduction and improved demisability. We also analysed how the relative importance of these two objectives can modify the selection of materials: if minimizing the heat to disintegration were valued more highly than lightness, for example, the new best candidates would become tin alloys. Our analysis, furthermore, suggested the importance of Liquid Crystal Polymer as the sole plastic material approaching the performance of the best metal choices. This contribution, thus, provides novel insight in the field of 3D-printed materials for the fast-growing CubeSat segment, complying with the debris mitigation initiatives promoted by space agencies and institutions. (C) 2020 COSPAR. Published by Elsevier Ltd. All rights reserved.

Accurate short-term forecasting of photovoltaic (PV) power is indispensable for controlling and designing smart energy management systems for microgrids. In this paper, different kinds of deep learning neural networks (DLNN) for short-term output PV power forecasting have been developed and compared: Long Short-Term Memory (LSTM), Bidirectional LSTM (BiLSTM), Gated Recurrent Unit (GRU), Bidirectional GRU (BiGRU), One-Dimension Convolutional Neural Network (CNN1D), as well as other hybrid configurations such as CNN1D-LSTM and CNN1D-GRU. A database of the PV power produced by the microgrid installed at the University of Trieste (Italy) is used to train and comparatively test the neural networks. The performance has been evaluated over four different time horizons (1 min, 5 min, 30 min and 60 min), for one-Step and multi-step ahead. The results show that the investigated DLNNs provide very good accuracy, particularly in the case of 1 min time horizon with one-step ahead (correlation coefficient is close to 1), while for the case of multi- step ahead (up to 8 steps ahead) the results are found to be acceptable (correlation coefficient ranges between 96.9% and 98%). (c) 2021 Elsevier Ltd. All rights reserved.

ABSTRACTTo overcome the complications connected to the treatment of coronary atherosclerosis by means of percutaneous transluminal angioplasty followed by stent implantation, the in situ release of antiproliferative nucleic acid based drugs (NABD) seems a promising approach. For their fragile nature, NABD cannot be released from drug eluting stents but they need to be embedded in a soft gel coating the coronary wall (endoluminal gel paving). This article deals with the thermal fate, once in the catheter, of a polymer blend composed by pluronic, giving rise to a soft gel in water upon temperature rise, and alginate, a natural polysaccharide giving origin to a strong gel in the presence of divalent cations. Simulations reveal that while the formation of a pregel is rapidly achieved, the formation of a mature gel takes a much longer time with respect to the residence time of the polymer blend inside the catheter. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48539.

As electric vehicles gain acceptance, an increasing number of households consider the possibility of buying the bundle including an electric car, a photovoltaic system, and a battery storage unit. Apart from the attractive environmental benefits, a relevant uncertainty concerns the economic convenience of such a choice. Since many variables play a role, we set up a total cost of ownership model to evaluate whether, and under which conditions, the bundle is cost-competitive relative to buying an electric car only (and charging it from the electrical grid) or a conventional combustion engine car. By combining, for the first time, such an economic model with an energy model and a driving profile model, we find that the degree of electricity self-production used to charge the electric car might be very high, varying from 90% to 62%, depending on the annual distance traveled. The cost of such electricity varies widely and can be lower than the grid electricity price when fiscal incentives are available and for long annual distances traveled. A smart charging practice based on both economic factors and weather forecast can greatly enhance self-sufficiency, i.e., independence from the electrical grid. We estimate that, given the current Italian financial incentives, 10,000 km/year are needed to make the electric car cost-competitive with respect to an equivalent petrol-fueled one. Such threshold increases to more than 25,000 km/year if financial incentives are removed.