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A considerable body of empirical evidence indicates that conflict affects reproductive behaviour, often resulting in an increased fertility rate due to higher child mortality and limited access to healthcare services. However, we know much less about the effect of peace in a post-conflict setting. This study explores how the external provision of security affects fertility by focusing on the UN intervention in Liberia. We combine DHS birth history data with information on road distance to UN military compounds and find that women living in the proximity of peacekeepers have lower fertility rates in the deployment period. This is due to parents prioritizing quality over quantity: peacekeepers improve maternal and child health and encourage family planning by enabling donors and humanitarian actors to deliver infrastructures and services and facilitating citizens’ access to such services. We also provide evidence that the UN mission revitalizes local economic activities, thus increasing the opportunity cost of childbearing.

The present study reports on the synthesis of a new alkoxysilane-bearing light-responsive cinnamyl group and its application as a surface functionalization agent for the development of SiO2 nanoparticles (NPs) with photoreversible tails. In detail, cinnamic acid (CINN) was activated with N-hydroxysuccinimide (NHS) to obtain the corresponding NHS-ester (CINN-NHS). Subsequently, the amine group of 3-aminopropyltriethoxysilane (APTES) was acylated with CINN-NHS leading to the generation of a novel organosilane, CINN-APTES, which was then exploited for decorating SiO2 NPs. The covalent bond to the silica surface was confirmed by solid state NMR, whereas thermogravimetric analysis unveiled a functionalization degree much higher compared to that achieved by a conventional double-step post-grafting procedure. In light of these intriguing results, the strategy was successfully extended to naturally occurring sepiolite fibers, widely employed as fillers in technological applications. Finally, a preliminary proof of concept of the photoreversibility of the obtained SiO2@CINN-APTES system has been carried out through UV diffuse reflectance. The overall outcomes prove the consistency and the versatility of the methodological protocol adopted, which appears promising for the design of hybrid NPs to be employed as building blocks for photoresponsive materials with the ability to change their molecular structure and subsequent properties when exposed to different light stimuli.

Magnetic chitosan composite (MCC) made by chitosan matrix embedding magnetite/maghemite were developed for the removal of toxic Cu(II), Pb(II), and Ni(II) from water. Thermogravimetric (TGA) and Zeta potential analyses showed that MCC contains ca. 50 wt % of chitosan and presents a value of isoelectric point (pHIEP) around 8-8.5. The magnetization curve revealed a saturation magnetization of 12 emu g−1, which indicates that MCC can be easily recovered by magnetic separation. Adsorption of the heavy metals to MCC reached equilibrium within 120 min with maximum uptakes of 108.9 mg g−1, 216.8 mg g−1 and 220.9 mg g−1 for Ni(II), Cu(II) and Pb(II), respectively. The results show that the amino and hydroxyl functional groups of chitosan are involved in the adsorption process. The reported adsorption capacity from organic pollutants, such as hydrocarbons, along with the high adsorption capacity shown for heavy metals, point out MCC being a promising versatile adsorbent for wastewater treatments.

Il saggio prende in considerazione le letture di Elsa Morante in ambito antropologico e etnografico, sulla base dei libri da lei posseduti e conservati nel Fondo Morante della Biblioteca Nazionale Centrale di Roma. L'attenzione riservata a Ernesto De Martino appare complessivamente modesta; assai più vivo è l'interesse che la scrittrice dimostra verso l'opera di Mircea Eliade, più consono alle sue inclinazioni e alla sua sensibilità. Fra i punti di contatto spiccano l'idea di storia e la fascinazione per la sapienza orientale.

This study evaluates the effectiveness of using different plasma treatments to favor the compatibility between rubber and a cement matrix in composites, thus leading to a different surface reactivity of the rubber component. Plasma-treated rubbers were introduced into two different types of concrete. Mechanical tests highlighted that Portland concrete composites filled with N2/H2 plasma-treated rubber had increased flexural strength, toughness, and compression strength compared to composites containing untreated rubber. A scaling law is also proposed to qualitatively discriminate between related effects due to topological/roughness or intrinsic/chemical adhesion modifications. Plasma treatment can improve both intrinsic adhesion and roughness of the rubber–cement interface and thus the overall concrete strength and toughness.

In the last decades, magnetic ceramics are very appealing materials that find applicationsin several technologic fields. Among these, iron oxides nanoparticles are the main relevantones due to their low-cost as naturally occurring substrates. However, depending on theapplication, it can be necessary to induce a specific shape and size control over the finalmorphology, and consequently a proper synthetic route becomes mandatory. Hence, thisdocument provides a summary of the main relevant chemical, physical, thermal, and bio-logical methods to induce a certain degree of morphological control in iron oxides. The mainfocus of this document relies on highlighting the principal guidelines, unveiling both advan-tages and disadvantages of each method in terms of morphology control in the resultingproducts. Lastly, a particular emphasis has been dedicated toward the industrial feasibilityof all processes here discussed.

Zirconium oxide is one of the most promising ceramic materials as it finds applications in several high-level technological fields, ranging from biomedicine to sensing. Zirconium oxide is characterized by showing very uncommon properties for being a ceramic substrate, such as a certain plastic behavior once subjected to mechanical stress, a naturally occurring phase transformation toughening, as well as a dramatic sensibility toward water-induced aging (if hydrothermally treated). In general, all these properties are strictly correlated with the tetragonal-to-monoclinic interphase transformation and, consequently, driven by the stabilization of the tetragonal phase. Hence, in this study, a summary of the main relevant principles guiding zirconium oxide interphase transformations is proposed, highlighting the important role of stabilizers and the correlation between microstructure and doping. A particular emphasis has been dedicated to the thermodynamics behind these phenomena.

The Lab4treat experience has been developed to demonstrate the use of magnetic materials in environmental applications. It was projected in the frame of the European project Mat4Treat, and it was tested several times in front of different audiences ranging from school students to the general public in training and/or divulgation events. The experience lends itself to discuss several aspects of actuality, physics and chemistry, which can be explained by modulating the discussion depth level, in order to meet the interests of younger or more experienced people and expand their knowledge. The topic is relevant, dealing with the recycling of urban waste and water depollution. The paper is placed within the field of water treatment for contaminant removal; therefore, a rich collection of recent (and less recent) papers dealing with magnetic materials and environmental issues is described in the Introduction section. In addition, the paper contains a detailed description of the experiment and a list of the possible topics which can be developed during the activity. The experimental approach makes the comprehension of scientific phenomena effective, and, from this perspective, the paper can be considered to be an example of interactive teaching.

Thermo-gravimetric analysis coupled to time/temperature-resolved FTIR spectroscopy of evolved gases was used to measure the vinyl alcohol units content in EVOH copolymer. Pure homopolymers were used as references. The quantitative analysis here proposed is based on the calculation of integral profiles relative to FTIR signals of water molecules evolved during the thermal degradation (pyrolysis) of vinyl alcohol units.

Biowaste-derived substances isolated from green compost (BBS-GC) are environmentally friendly reactants similar to humic substances, which contain multiple functionalities, that are suitable for adsorbing different kinds of pollutants in wastewater. Herein, sodium alginate (derived from brown algae) cross-linked with both Ca2+ ions and BBS-GC in the form of hydrogels and dried films are proposed as green, easy-to-form, and handleable materials for tertiary water treatments. The results show that both hydrogels and films are mechanically stable and can effectively remove differently charged dyes through an adsorption mechanism that can be described by the Freundlich model. BBS-GC-containing gels always performed better than samples prepared without BBS-GC, revealing that such unconventional materials can integrate waste valorization and water decontamination, potentially providing social and environmental benefits.

Thermoresponsive poly(N-isopropylacrylamide)-grafted silica nanoparticles (SiNPs) have been synthesized and fully characterized by ATR-FTIR, TGA, HRTEM, BET and DLS analysis. Hybrid solid phase extraction (SPE) beds with tuneable pore size and switchable surface chemistry were prepared by packing the polymergrafted nanoparticles inside SPE cartridges. The cartridges were tested by checking the thermoregulated elution of model compounds, namely methylene blue, caffeine and amoxicillin. Extraction of the analytes and regeneration of the interaction sites on the sorbent surface was carried out entirely in water solution by changing the external temperature below and above the lower critical solution temperature (LCST) of the polymer. The results demonstrate that the elution of model compounds depends on the temperature-regulated size of the inter-particle voids and on the change of surface properties of the PNIPAM-grafted nanoparticles from hydrophilic to hydrophobic.

The growing utilization of renewable and residual biomasses for environmental preservation and remediation are important goals to be pursued to minimize the environmental impact of human activities. In this paper, sodium alginate (derived from brown algae) was crosslinked using chitosan (mainly derived from the exoskeleton of crustaceans) in the presence of biowaste-derived substances isolated from green compost (BBS-GC), to produce hydrogels and dried films. The obtained materials were tested as adsorbents for wastewater remediation. To this purpose, gels were characterized using a multi-analytical approach and used as active substrates for the removal of three differently-charged molecules, chosen as model pollutants: crystal violet, rhodamine B, and orange II. The effectiveness of the gel formulations was demonstrated and attributed to the variety of active functionalities introduced by the different precursors, the structural factors and the peculiar physicochemical properties of the resulting materials.

Magnetic structures have attracted a great interest due to their multiple applications, from physics to biomedicine. Several techniques are currently employed to investigate magnetic characteristics and other physicochemical properties of magnetic structures. The major objective of this review is to summarize the current knowledge on the usage, advances, advantages, and disadvantages of a large number of techniques that are currently available to characterize magnetic systems. The present review, aiming at helping in the choice of the most suitable method as appropriate, is divided into three sections dedicated to characterization techniques. Firstly, the magnetism and magnetization (hysteresis) techniques are introduced. Secondly, the visualization methods of the domain structures by means of different probes are illustrated. Lastly, the characterization of magnetic nanosystems in view of possible biomedical applications is discussed, including the exploitation of magnetism in imaging for cell tracking/visualization of pathological alterations in living systems (mainly by magnetic resonance imaging, MRI).

N-rich biochars were obtained via pyrolysis treatment of chitosan (a low-cost biopolymer from natural biomasses) at mild conditions (in the 284 °C–540 °C range), thus offering an energy efficient and low carbon footprint synthesis. These low surface area N-doped biochars were morphologically and physicochemically characterized, and tested as hosting material in lithium-sulfur (Li-S) batteries. Sulfur/biochars cathodes thus obtained showed good capacity retention and improved Coulombic efficiency compared to a standard N-rich high surface area carbon and multiwalled carbon nanotubes (MWCNT) reference substrates. Such enhanced electrochemical properties are attributable to the better retention of Li polysulfides by means of the residual functionalities still present in the biochars, thus making the valorization of chitosan potentially appealing even in the industrial sector related to the development of energy storage devices.

Since waste tires constitute a serious environmental concern, several studies are devoted to the use of finely divided recycled rubber for the production of rubberized concrete by partial substitution of the mineral aggregate fraction. The introduction of rubber into concrete presents several advantages (e.g., improvement of toughness and thermal/electrical/acoustic insulation capacities). Unfortunately, the addition of a high content of rubber into concrete causes an important loss of mechanical resistance of the final composite. In this context, several scientific studies are devoted to investigate the best technical solutions for favoring the interfacial adhesion between rubber and cement paste, but the interpretation of the literature is often misleading. To overcome this issue, the metadata extrapolated from the single scientific works were critically re-analyzed, forming reference diagrams where the variability fields of the dierent rubber concrete formulations (in terms of mechanical responses as a function of the rubber content) were defined and the best performances discussed. This study evidenced the twofold role of reference diagrams, able in both presenting the data in an unambiguous manner (for a successful comparison) and providing the guidelines for future works in this research field.

After a brief historical classification of the main discoveries related to magnetism, magnetic materials have been rationally ordered in a simple (and hopefully clear) organization. A great effort was realized in the description of the different synthetic approaches for the preparation of magnet-sensitive materials (in particular, focusing on iron oxides). The principal useful techniques for evaluating the magnetic properties in materials (namely, MFM and magnetization hysteresis) have been presented, providing useful examples in order to understand both the potentiality and limits of these characterization methods. Finally, the application of magnet-sensitive materials in water remediation processes has been provided, highlighting both advantages and disadvantages of their use compared to conventional treatments. In this context, the action mechanism and the possible integration of this class of materials into processes involving wastewater treatments are widely discussed, keeping an eye toward the future perspectives.

Soluble biopolymers (SBO) are research products obtained from alkaline hydrolysis of municipal and agriculture bio-residues. They contain a mix of soluble macromolecules with different C types and functional groups. These features make SBO multipurpose products for the chemical industry, agriculture and animal husbandry. As such, they may contribute to the development of bio-based circular economy by recycling renewable carbon over urban and agriculture environments. To foster production and commercialization, assessment of SBO’s compliance with countries’ regulations is mandatory. The authors performed the present in vivo pigs study to investigate quality, safety, and efficacy of SBO’s as animal feed supplement. Total 106 male and female piglets were fed 42 days with protein-based diets containing 0.1 and 0.2 % SBO. Pigs grew from average 7.7 to 26 kg. Average mortality rate was 3.9 %. Relatively to control diets with no added SBO, the diets containing 0.1 and 0.2 % SBO evidenced no significant effects on pigs’ growth, mortality, and anatomy and pathology of dead animals. A previous rabbit study reported similar results for SBO supplemented diets. The authors discuss the economic and environmental implications of the results in relation to SBO potential marketability.

This work reports the demineralisation of soluble biorganic hyrolysates (SBOs) obtained from three materials sampled from a municipal biowaste treatment plant. The SBOs contain mineral and organic matter. They are promising bio‐based multipurpose products due to their properties as biosurfactants, chemicals for the manufacture of plastics, and fertilizers for plant growth. Demineralisation of SBOs was carried out by HCl ion exchange and HF washing to assess its effect on the pristine product chemical composition and properties. The demineralized products (SBOs‐DM) were characterized by elemental analysis, potentiometric titration, 13C‐NMR spectroscopy and surface tension measurements. They were compared with pristine SBOs. The following results were obtained: ash content 0.2‐1.1% in SBOs‐DM vs. 15–28% in pristine SBOs; lower aliphatic/aromatic C ratio in SBOs‐DM (0.8‐2.0) than in pristine SBOs (1.3‐3.4); higher critical (mineral free) micellar concentration for SBOs‐DM (1‐2.7 g L−1) than for pristine SBOs (1‐2.3 g L−1). The potential applications of SBOs‐DM and pristine SBOs are discussed.

In this study, cellulose fibers were chemically functionalized under mild conditions by introducing palmitate groups in order to produce a hydrophobic cellulose-based ester. The effectiveness and the degree of functionalization were evaluated by FTIR spectroscopy and thermogravimetric analysis, whereas the structural integrity was confirmed by XRD measurements. The prepared materials were tested in water remediation processes from fatty oils mixtures from both animal (cod liver oil) and vegetable (sunflower oil) sources. Experimental kinetic measurements, rationalized by means of the most common models, show that the best performances were reached toward the sunflower oil, hence proving the promising application of such green materials as a sustainable alternative tool for oil–water remediation processes.

Particularly-shaped silver nanostructures are successfully applied in many scientific fields, such as nanotechnology, catalysis, (nano)engineering, optoelectronics, and sensing. In recent years, the production of shape-controlled silver-based nanostructures and the knowledge around this topic has grown significantly. Hence, on the basis of the most recent results reported in the literature, a critical analysis around the driving forces behind the synthesis of such nanostructures are proposed herein, pointing out the important role of surface regulating agents in driving crystalline growth by favoring (or opposing) development along specific directions. Additionally, growth mechanisms of the different morphologies considered here are discussed in depth, and critical points highlighted